General Binomial Expansion (Edexcel A Level Maths: Pure): Exam Questions

Exam code: 9MA0

5 hours49 questions
12 marks

Find, in ascending powers of x, the binomial expansion of

         open parentheses 1 minus x close parentheses to the power of negative 1 end exponent

up to and including the term in x squared.

Did this page help you?

2a
Sme Calculator
2 marks

Find the first three terms, in ascending powers of x, of the binomial expansion of

        left parenthesis 1 plus x right parenthesis to the power of negative 2 end exponent

giving each term in simplest form.

2b
Sme Calculator
1 mark

State the range of values of x for which the expansion in part (a) is valid.

Did this page help you?

33 marks

Find, in ascending powers of x, the binomial expansion of

        left parenthesis 1 plus 2 x right parenthesis to the power of negative 1 half end exponent

up to and including the term in x cubed.

Did this page help you?

4a3 marks

Find the first three terms, in ascending powers of x, of the binomial expansion of

      space open parentheses 1 minus 1 half x close parentheses to the power of 1 third end exponent

giving each term in simplest form.

4b
Sme Calculator
1 mark

State the range of values of x for which the expansion in part (a) is valid.

Did this page help you?

51 mark

Find the coefficient of the term in x squared in the binomial expansion of

        left parenthesis 1 minus 3 x right parenthesis to the power of negative 3 end exponent

Did this page help you?

6a2 marks

Given that x is small, so that x cubed and higher powers of x can be ignored, show that

            open parentheses 1 minus 1 third x close parentheses to the power of negative 2 end exponent almost equal to 1 plus 2 over 3 x plus 1 third x squared

6b
Sme Calculator
1 mark

By substituting x equals 0.18 into the result from part (a), find an estimate for the value of left parenthesis 0.94 right parenthesis to the power of negative 2 end exponent.

Did this page help you?

7a1 mark

Show that

         square root of 4 minus 4 x end root identical to 2 left parenthesis 1 minus x right parenthesis to the power of 1 half end exponent

7b2 marks

Hence find, in ascending powers of x, the first three terms of the binomial expansion of

      square root of 4 minus 4 x end root

giving each term in simplest form.

7c
Sme Calculator
2 marks

Use x equals 0.02 and your expansion from part (b) to find an approximation to  2 square root of 0.98 end root.

Did this page help you?

1a
Sme Calculator
3 marks

Find the first four terms, in ascending powers of x, of the binomial expansion of

open parentheses 1 plus 8 x close parentheses to the power of 1 half end exponent

giving each term in simplest form.

1b2 marks

Explain how you could use x equals 1 over 32 in the expansion to find an approximation for square root of 5.

There is no need to carry out the calculation.

Did this page help you?

2a2 marks

Find the first three terms, in ascending powers of x, of the binomial expansion of

               square root of 1 plus 2 x end root 

giving each term in simplest form.

2b1 mark

State the range of values of x for which the expansion in part (a) is valid.

2c
Sme Calculator
2 marks

By choosing a suitable value of x, use your expansion from part (a) to estimate square root of 1.06 end root

Give your estimate to 3 significant figures.

Did this page help you?

33 marks

Find, in ascending powers of x, the binomial expansion of

         1 over open parentheses 1 minus x close parentheses squared

up to and including the term in x cubed.

Give each term in simplest form.

Did this page help you?

42 marks

The function straight f left parenthesis x right parenthesis is given by

           straight f left parenthesis x right parenthesis equals left parenthesis 1 minus p x right parenthesis to the power of negative 4 end exponent

where p is an integer.

Find, in terms of p, the coefficient of the term in x cubed in the binomial expansion of straight f left parenthesis x right parenthesis.

Did this page help you?

54 marks

Find, in ascending powers of x, the binomial expansion of

1 over open parentheses 4 plus 8 x close parentheses squared

up to and including the term in x cubed.

Give each term in simplest form.

Did this page help you?

6a2 marks

Given that

         fraction numerator 5 minus x over denominator open parentheses 1 plus x close parentheses open parentheses 1 minus x close parentheses end fraction identical to fraction numerator A over denominator 1 plus x end fraction plus fraction numerator B over denominator 1 minus x end fraction

find the values of A and B.

6b4 marks

Find the first three terms, in ascending powers of x, of the binomial expansions of

(i)  3 left parenthesis 1 plus x right parenthesis to the power of negative 1 end exponent

(ii) 2 left parenthesis 1 minus x right parenthesis to the power of negative 1 end exponent

6c1 mark

Hence show that the first three terms, in ascending powers of x, in the binomial expansion of

            fraction numerator 5 minus x over denominator open parentheses 1 plus x close parentheses open parentheses 1 minus x close parentheses end fraction

are

               5 minus x plus 5 x squared

6d1 mark

Find the range of values of x for which the expansion of fraction numerator 5 minus x over denominator open parentheses 1 plus x close parentheses open parentheses 1 minus x close parentheses end fraction converges.

Did this page help you?

7a2 marks

Use the binomial expansion to show that the first three terms in the expansion of  left parenthesis 1 plus 2 x right parenthesis to the power of negative 3 end exponent are  

1 minus 6 x plus k x squared

where k is a constant to be found.

7b3 marks

Hence find the first three terms, in ascending powers of x, of the binomial expansion of

fraction numerator 1 plus x over denominator open parentheses 1 plus 2 x close parentheses cubed end fraction

giving each term in simplest form.

State also the range of values of x for which the expansion is valid.

Did this page help you?

8a3 marks

The function straight f left parenthesis x right parenthesis is given by

straight f left parenthesis x right parenthesis equals open parentheses 1 minus 1 half x close parentheses to the power of 1 half end exponent

(i) Expand straight f left parenthesis x right parenthesis in ascending powers of x up to and including the term in x squared.

(ii) Find the range of values of x for which this expansion is valid.

8b3 marks

The function straight g left parenthesis x right parenthesis is given by

straight g left parenthesis x right parenthesis equals left parenthesis 2 plus x right parenthesis to the power of negative 2 end exponent

(i) Expand straight g left parenthesis x right parenthesis in ascending powers of x up to and including the term in x squared.

(ii) Find the range of values of x for which this expansion is valid.

8c3 marks

(i) Find the expansion of fraction numerator square root of 1 minus 1 half x end root over denominator open parentheses 2 plus x close parentheses squared end fraction in ascending powers of x, up to and including the term in x squared.

(ii) Find the range of values of x for which this expansion is valid.

Did this page help you?

9a3 marks

The function straight f left parenthesis x right parenthesis is given by

            straight f left parenthesis x right parenthesis equals square root of 4 minus s x end root

where s is a non-zero integer.

In the binomial expansion of straight f left parenthesis x right parenthesis, find in terms of s

(i) the coefficient of the term in x

(ii) Find the coefficient of the term in x squared

9b1 mark

In the binomial expansion of straight f left parenthesis x right parenthesis, the coefficient of the term in x is equal to the coefficient of the term in x squared.

Find the value of s.

Did this page help you?

103 marks

Two functions are given by

straight f open parentheses x close parentheses equals square root of 1 plus a x end root

straight g open parentheses x close parentheses equals cube root of 1 minus a x end root

where a is a non-zero constant.

In their binomial expansions, the coefficient of the term in x squared from straight f left parenthesis x right parenthesis is equal to the coefficient of the term in x from straight g left parenthesis x right parenthesis.

Find the value of a.

Did this page help you?

11a2 marks

Express fraction numerator 2 over denominator open parentheses 1 minus x close parentheses open parentheses 1 plus x close parentheses end fraction in partial fractions.

11b3 marks

Find the first three terms, in ascending powers of x, of the binomial expansions of

(i)  open parentheses 1 minus x close parentheses to the power of negative 1 end exponent

(ii) open parentheses 1 plus x close parentheses to the power of negative 1 end exponent

11c2 marks

Hence show that 

fraction numerator 2 over denominator open parentheses 1 minus x close parentheses open parentheses 1 plus x close parentheses end fraction almost equal to alpha plus beta x squared

where alpha and beta are constants to be found.

11d1 mark

Find the range of values of x for which the expansion in part (c) is valid.

Did this page help you?

12
Sme Calculator
2 marks

Find, in ascending powers of x, the binomial expansion of

            1 over open parentheses 1 minus 2 x close parentheses cubed

up to and including the term in x cubed.

Give each term in simplest form.

Did this page help you?

134 marks

Find, in ascending powers of x, the binomial expansion of

         1 over open parentheses 4 plus x close parentheses cubed

up to and including the term in x cubed.

Give each term in simplest form.

Did this page help you?

14a2 marks

Use the binomial expansion to expand open parentheses 1 minus begin inline style 1 half end style x close parentheses to the power of begin inline style 1 third end style end exponent  up to and including the term in x squared.

Give each term in simplest form.

14b2 marks

Hence expand  open parentheses 1 minus x close parentheses open parentheses 1 minus 1 half x close parentheses to the power of 1 third end exponent up to and including the term in x squared.

Did this page help you?

154 marks

Find, in ascending powers of x, the binomial expansion of

         1 over open parentheses 1 minus 1 third x close parentheses to the power of 4

up to and including the term in x cubed.

Give each term in simplest form.

Did this page help you?

16
Sme Calculator
4 marks

Find, in ascending powers of x, the binomial expansion of

         1 over open parentheses 3 minus 2 x close parentheses to the power of 4

up to and including the term in x cubed.

Give each term in simplest form.

Did this page help you?

1a4 marks

In this question you must show all stages of your working.

Solutions relying entirely on calculator technology are not acceptable.

Find the first three terms, in ascending powers of x, of the binomial expansion of

open parentheses 3 plus x close parentheses to the power of negative 2 end exponent

writing each term in simplest form.

1b
Sme Calculator
4 marks

Using the answer to part (a) and using algebraic integration, estimate the value of

integral subscript 0.2 end subscript superscript 0.4 end superscript fraction numerator 6 x over denominator open parentheses 3 plus x close parentheses squared end fraction space d x

giving your answer to 4 significant figures.

Did this page help you?

2a
Sme Calculator
4 marks

Find the first three terms, in ascending powers of x, of the binomial expansion of

fraction numerator 1 over denominator square root of 4 minus x end root end fraction

giving each coefficient in its simplest form.

2b2 marks

The expansion can be used to find an approximation to square root of 2

Possible values of x that could be substituted into this expansion are

  • x equals negative 14 because fraction numerator 1 over denominator square root of 4 minus x end root end fraction equals fraction numerator 1 over denominator square root of 18 end fraction equals fraction numerator square root of 2 over denominator 6 end fraction

  • x equals 2 because fraction numerator 1 over denominator square root of 4 minus x end root end fraction equals fraction numerator 1 over denominator square root of 2 end fraction equals fraction numerator square root of 2 over denominator 2 end fraction

  • x equals negative 1 half because fraction numerator 1 over denominator square root of 4 minus x end root end fraction equals fraction numerator 1 over denominator square root of 9 over 2 end root end fraction equals fraction numerator square root of 2 over denominator 3 end fraction

Without evaluating your expansion,

(i) state, giving a reason, which of the three values of x should not be used

(ii) state, giving a reason, which of the three values of x would lead to the most accurate approximation to square root of 2

Did this page help you?

3a
Sme Calculator
4 marks

Find the first four terms, in ascending powers of x, of the binomial expansion of

square root of 4 minus 9 x end root

writing each term in simplest form.

3b1 mark

A student uses this expansion with x equals 1 over 9 to find an approximation for square root of 3

Using the answer to part (a) and without doing any calculations, state whether this approximation will be an overestimate or an underestimate of square root of 3 giving a brief reason for your answer.

Did this page help you?

4a
Sme Calculator
4 marks

Use the first three terms, in ascending powers of x of the binomial expansion of

              open parentheses 1 plus 4 x close parentheses to the power of begin inline style 1 third end style end exponent

to estimate the value of cube root of 1.2 end root, giving your estimate to 3 significant figures.

4b2 marks

Explain why your estimate in part (a) is valid.

Did this page help you?

53 marks

In the binomial expansion of  open parentheses 1 minus begin inline style 1 fourth end style x close parentheses to the power of n where n is a negative integer, the coefficient of the term in x squared is begin inline style 3 over 8 end style.

Find the value of n.

Did this page help you?

6a6 marks

A function is given by

straight f open parentheses x close parentheses equals open parentheses 1 minus 1 third x close parentheses to the power of negative 1 end exponent open parentheses 2 minus x close parentheses to the power of negative 2 end exponent

Given that x is small, such that terms in x cubed and higher powers of x can be ignored, show that

        straight f open parentheses x close parentheses almost equal to 1 fourth plus 1 third x plus k x squared

where k is an exact constant to be found.

6b1 mark

Find the range of values of x for which the expansion in part (a) is valid.

6c
Sme Calculator
3 marks

Find, to 3 significant figures, the percentage error when using the approximation in part (a) to estimate straight f open parentheses 1 half close parentheses.

Show clear working.

Did this page help you?

74 marks

Two functions are given by

straight f open parentheses x close parentheses equals square root of 9 plus p x end root

straight g open parentheses x close parentheses equals fourth root of 16 plus p x end root

where p is a non-zero constant.

In their binomial expansions, the coefficient of the term in x squared from straight f left parenthesis x right parenthesis is equal to the coefficient of the term in x from straight g left parenthesis x right parenthesis.

Find the value of p.

Did this page help you?

84 marks

In the binomial expansion of 1 over open parentheses 3 plus p x close parentheses cubedwhere p not equal to 0, the coefficient of the term in x squared is double the coefficient of the term in x cubed

Find the value of  p.

Did this page help you?

9a3 marks

The functions straight f left parenthesis x right parenthesis and  straight g left parenthesis x right parenthesis are given by

straight f left parenthesis x right parenthesis equals open parentheses 4 plus 3 x close parentheses to the power of 1 half end exponent

straight g left parenthesis x right parenthesis equals open parentheses 9 minus 2 x close parentheses to the power of negative 1 half end exponent

Find the first three terms, in ascending powers of x, of the binomial expansion of straight f left parenthesis x right parenthesis.

9b3 marks

Find the first three terms, in ascending powers of x, of the binomial expansion of straight g left parenthesis x right parenthesis.

9c2 marks

Find the first three terms, in ascending powers of x, of the expansion of

square root of fraction numerator 4 plus 3 x over denominator 9 minus 2 x end fraction end root 

giving each term in simplest form.

9d1 mark

Find the range of values of x for which your expansion in part (c) is valid.

Did this page help you?

104 marks

In the expansion of  begin mathsize 20px style open parentheses 1 minus begin inline style 4 over 3 end style x close parentheses to the power of n end style where n is a rational number, the coefficient of the term in x squared is begin mathsize 20px style begin inline style negative 16 over 81 end style end style.

Find the possible values of n.

Did this page help you?

11a6 marks

Given that x is small, so that terms in x cubed and higher powers of x can be ignored, show that

         stretchy left parenthesis 2 plus 3 x stretchy right parenthesis to the power of negative 1 end exponent stretchy left parenthesis 3 minus 2 x stretchy right parenthesis to the power of negative 2 end exponent almost equal to 1 over 18 minus 1 over 108 x plus 19 over 216 x squared

11b1 mark

Find the range of values of x for which the approximation in part (a) is valid.

11c
Sme Calculator
2 marks

Find, to 1 decimal place, the percentage error when using the approximation in part (a) to estimate the value of fraction numerator 1 over denominator stretchy left parenthesis 2 plus 3 x stretchy right parenthesis stretchy left parenthesis 3 minus 2 x stretchy right parenthesis squared end fraction at x equals 0.1

Did this page help you?

12a3 marks

Express fraction numerator 12 minus x over denominator open parentheses x plus 2 close parentheses open parentheses 3 minus x close parentheses end fraction  in partial fractions.

12b5 marks

Use binomial expansions to show that

fraction numerator 12 minus x over denominator open parentheses x plus 2 close parentheses open parentheses 3 minus x close parentheses end fraction equals 2 minus 1 half x plus m x squared plus...

where m is a constant to be found.

12c1 mark

Find the range of validity of x for the expansion in part (b).

Did this page help you?

13a4 marks

In the binomial expansion of  square root of 4 plus begin inline style p over q end style x end root   where p less than 0 less than q, the coefficient of the term in x squared is equal to the coefficient of the term in x cubed.

Show that p equals negative 8 q.

13b2 marks

Given that the product of p and q is negative 8, find the values of p and q.

Did this page help you?

14a2 marks

Express fraction numerator 1 minus 7 x over denominator open parentheses x plus 2 close parentheses open parentheses 3 minus x close parentheses end fraction  in the form  fraction numerator A over denominator x plus 2 end fraction plus fraction numerator B over denominator 3 minus x end fraction, where A and B are integers to be found.

14b5 marks

Hence find the expansion of fraction numerator 1 minus 7 x over denominator open parentheses x plus 2 close parentheses open parentheses 3 minus x close parentheses end fraction, in ascending powers of x, up to and including the term in x squared.

Did this page help you?

15a6 marks

Given that x is small, so that terms in x cubed and higher powers of x can be ignored, show that

open parentheses 4 minus 3 x close parentheses to the power of negative 2 end exponent open parentheses 2 minus x close parentheses to the power of negative 3 end exponent almost equal to 1 over 128 plus 3 over 128 x plus 87 over 2048 x squared

15b1 mark

Find the range of values of x for which the approximation in part (a) is valid.

15c
Sme Calculator
3 marks

Find, to 1 decimal place, the percentage error when using the approximation in part (a) to estimate the value of fraction numerator 1 over denominator open parentheses 4 minus 3 x close parentheses squared open parentheses 2 minus x close parentheses cubed end fraction at x equals 0.2

Did this page help you?

1a
Sme Calculator
4 marks

straight f open parentheses x close parentheses equals fraction numerator 50 x squared plus 38 x plus 9 over denominator open parentheses 5 x plus 2 close parentheses squared open parentheses 1 minus 2 x close parentheses end fraction space space space space space x not equal to negative 2 over 5 space space space x not equal to 1 half

Given that straight f open parentheses x close parentheses can be expression in the form

fraction numerator A over denominator 5 x plus 2 end fraction plus B over open parentheses 5 x plus 2 close parentheses squared plus fraction numerator C over denominator 1 minus 2 x end fraction

where A, B and C are constants,

(i) find the value of B and the value of C,

(ii) show that A equals 0.

1b
Sme Calculator
7 marks

(i) Use binomial expansions to show that, in ascending powers of x

straight f open parentheses x close parentheses equals p plus q x plus r x squared plus...

where p, q and r are simplified fractions to be found.

(ii) Find the range of values of x for which this expansion is valid.

Did this page help you?

2a
Sme Calculator
6 marks

Use binomial expansions to show that square root of fraction numerator 1 plus 4 x over denominator 1 minus x end fraction end root almost equal to 1 plus 5 over 2 x minus 5 over 8 x squared.

2b1 mark

A student substitutes x equals 1 half into both sides of the approximation shown in part (a) in an attempt to find an approximation to square root of 6.

Give a reason why the student should not use x equals 1 half.

2c
Sme Calculator
3 marks

Substitute x equals 1 over 11 into

square root of fraction numerator 1 plus 4 x over denominator 1 minus x end fraction end root equals 1 plus 5 over 2 x minus 5 over 8 x squared

to obtain an approximation to square root of 6. Give your answer as a fraction in its simplest form.

Did this page help you?

3a
Sme Calculator
5 marks

Use the first three terms, in ascending powers of x, in the binomial expansion of

         fraction numerator 1 over denominator square root of 1 minus 1 half x end root end fraction

to estimate the value of fraction numerator 1 over denominator square root of 0.95 end root end fraction, giving your estimate to 2 decimal places.

3b2 marks

Explain why you would not be able to use the expansion in part (a) to estimate fraction numerator 1 over denominator square root of 3 end fraction.

Did this page help you?

45 marks

Find the first three terms in ascending powers of xof the binomial expansion of

fraction numerator 1 minus x over 2 over denominator square root of 9 plus 3 x end root end fraction

giving each term in simplest form.

Did this page help you?

55 marks

In the binomial expansion of   fraction numerator 1 over denominator cube root of 8 plus 2 q x end root end fraction where q not equal to 0,  the coefficient of the term in x squared is one-seventh of the coefficient of the term in x cubed

Find the value of q.

Did this page help you?

66 marks

Expand

cube root of fraction numerator 8 minus x over denominator 8 plus 2 x end fraction end root

in ascending powers of x, up to and including the term in x squared

Find also the range of values of x for which this expansion is valid.

Did this page help you?

7a4 marks

Express fraction numerator 4 plus 5 x minus x squared over denominator open parentheses 1 minus x close parentheses open parentheses 1 plus x close parentheses squared end fraction  in partial fractions.

7b6 marks

Use binomial expansions to show that, in ascending powers of x,

fraction numerator 4 plus 5 x minus x squared over denominator open parentheses 1 minus x close parentheses open parentheses 1 plus x close parentheses squared end fraction equals a plus b x plus c x squared plus...

where a, b and c are constants to be found.

7c1 mark

Find the range of values of x for which the expansion is valid.

Did this page help you?

85 marks

Two functions are given by

 straight f left parenthesis x right parenthesis equals square root of 4 plus a x end root 

straight g left parenthesis x right parenthesis equals fourth root of 16 plus b x end root

where a and b are non-zero constants.

The binomial expansions of  straight f left parenthesis x right parenthesis  and  straight g left parenthesis x right parenthesis have the following properties:

  • The coefficient of the x cubed term in the expansion of straight f open parentheses x close parentheses is 72 times larger than the coefficient of the x squared term in the expansion of straight g open parentheses x close parentheses

  • The coefficient of the x term in the expansion of straight f open parentheses x close parentheses is 24 times larger than the coefficient of the x term in the expansion of straight g open parentheses x close parentheses

Find the values of a and b.

Did this page help you?

9a6 marks

Use binomial expansions to show that, in ascending powers of x

15 open parentheses x minus 4 close parentheses to the power of negative 1 end exponent open parentheses 5 x minus 2 close parentheses to the power of negative 1 end exponent equals a plus b x plus c x squared plus...

where a, b and c are constants to be found.

9b2 marks

Explain why the expansion found in part (a) cannot be used to estimate the value of

fraction numerator 15 over denominator open parentheses 0.6 minus 4 close parentheses open parentheses 5 cross times 0.6 minus 2 close parentheses end fraction

Did this page help you?

10a10 marks

Use binomial expansions to show that, in ascending powers of x,

fraction numerator 2 open parentheses 2 minus 5 x plus x squared close parentheses over denominator open parentheses x plus 2 close parentheses open parentheses 2 minus x close parentheses squared end fraction equals alpha plus beta x plus gamma x squared plus...

where alpha, beta and gamma are constants to be found.

10b1 mark

Find the range of values of x for which the expansion is valid.

Did this page help you?

115 marks

In the expansion of open parentheses 16 minus 2 x close parentheses to the power of n where n is a rational number, the coefficient of the term in x squared is

5 cross times 2 to the power of 4 n minus 11 end exponent

Given that vertical line n vertical line less than 1, find the value of n.

Did this page help you?