Operations with Complex Numbers (Edexcel International A Level (IAL) Further Maths: Further Pure 1): Exam Questions

Exam code: YFM01

1 hour8 questions
1
5 marks

2 z plus z to the power of asterisk times equals fraction numerator 3 plus 4 straight i over denominator 7 plus straight i end fraction

Find z, giving your answer in the form a plus b straight i, where a and b are real constants. You must show all your working.

2a
3 marks

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

Solutions relying entirely on calculator technology are not acceptable.

The complex number z is defined by

z equals negative 3 plus 4 straight i

Determine open vertical bar z squared minus 3 close vertical bar

2b
3 marks

Express 50 over z to the power of asterisk times in the form k z , where k is a positive integer.

2c
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2 marks

Hence find the value of arg blank space open parentheses 50 over z to the power of asterisk times close parentheses

Give your answer in radians to 3 significant figures.

3a
4 marks

Given that

fraction numerator 3 z minus 1 over denominator 2 end fraction equals fraction numerator lambda plus 5 straight i over denominator lambda minus 4 straight i end fraction

where lambda is a real constant,

determine z, giving your answer in the form x plus y straight i, where x and y are real and in terms of lambda.

3b
2 marks

Given also that arg space z equals pi over 4

find the possible values of lambda.

4a
2 marks

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

Solutions relying entirely on calculator technology are not acceptable.

z subscript 1 equals 3 plus 2 straight i      z subscript 2 equals 2 plus 3 straight i      z subscript 3 equals a plus b straight i      a comma b element of straight real numbers

Determine the exact value of vertical line z subscript 1 plus z subscript 2 vertical line

4b
4 marks

Given that w equals fraction numerator z subscript 2 z subscript 3 over denominator z subscript 1 end fraction

Determine win terms of a and b, giving your answer in the form x plus straight i y , where x comma y element of straight real numbers

4c
2 marks

Given also that w equals 4 over 13 plus 58 over 13 straight i

Determine the value of a and the value of b

4d
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2 marks

Determine arg space w, giving your answer in radians to 4 significant figures.

5a
2 marks

z subscript 1 equals 3 plus 3 straight i      z subscript 2 equals p plus q straight i      p comma   q element of straight real numbers

Given that vertical line z subscript 1 z subscript 2 vertical line equals 15 square root of 2

determine vertical line z subscript 2 vertical line

5b
2 marks

Given also that p space equals space minus 4

determine the possible values of q

5c
2 marks

Show z subscript 1 and the possible positions for z subscript 2 on the same Argand diagram.

6a
2 marks

The complex numbers z subscript 1 and z subscript 2 are given by

z subscript 1 equals 3 plus 5 i    text and end text    z subscript 2 equals negative 2 plus 6 i

Show z subscript 1 and z subscript 2 on a single Argand diagram.

6b
4 marks

Without using your calculator and showing all stages of your working,

(i) determine the value of vertical line z subscript 1 vertical line

[1]

(ii) Express z subscript 1 over z subscript 2 in the form a space plus space b i

[3]

6c
2 marks

Hence determine the value of arg z subscript 1 over z subscript 2

Give your answer in radians to 2 decimal places.

7a
3 marks

The complex numbers z subscript 1, z subscript 2 and z subscript 3 are given by

z subscript 1 equals 2 minus i      z subscript 2 equals p minus i      z subscript 3 equals p plus i

where p is a real number.

Find fraction numerator z subscript 2 z subscript 3 over denominator z subscript 1 end fraction in the form a space plus space b i where a and b are real. Give your answer in its simplest form in terms of p.

7b
4 marks

Given that open vertical bar fraction numerator z subscript 2 z subscript 3 over denominator z subscript 1 end fraction close vertical bar equals 2 square root of 5

find the possible values of p.

8a
1 mark

The complex number z is defined by

z equals negative lambda plus 3 straight i where lambdais a positive real constant.

Given that the modulus of z is 5,

write down the value of lambda

8b
2 marks

determine the argument of z, giving your answer in radians to one decimal place.

8c
5 marks

In part (c) you must show detailed reasoning. Solutions relying on calculator technology are not acceptable.

Express in the form a space plus space i b where a and b are real,

(i) fraction numerator z plus 3 straight i over denominator 2 minus 4 straight i end fraction

(ii) z squared

8d
3 marks

Show on a single Argand diagram the points A, B, C and D that represent the complex numbers

z comma    z to the power of asterisk times comma    fraction numerator z plus 3 straight i over denominator 2 minus 4 straight i end fraction    text and end text    z squared