Exponential & Logarithms (Edexcel A Level Maths: Pure): Exam Questions

Exam code: 9MA0

2 hours44 questions
1
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3 marks

Find the value of

(i) 3 cubed

(ii) 4 to the power of negative 2 end exponent

(iii) 9 to the power of 0.5 end exponent

23 marks

Sketch the curve with equation

y equals a to the power of x space space space space space space space space a greater than 1

showing clearly any points of intersection with the coordinate axes.

State whether the graph shows exponential growth or exponential decay.

33 marks

State whether the following models represent exponential growth or exponential decay:

(i) y equals 3 to the power of negative 2 x end exponent

(ii) y equals 20 open parentheses 2 close parentheses to the power of x

(iii) y equals 30 a to the power of negative x end exponent where a greater than 1

4
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3 marks

Write down the value(s) of a in the following:

(i) space 3 to the power of a equals 27

(ii) space a to the power of 1 third end exponent equals 5

(iii) space 4 a squared equals 64

5
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3 marks

Write down the value of a in the following:

(i) space log subscript 3 a equals 4

(ii) space log subscript a space end subscript 216 equals 3

(iii) space log subscript 2 space end subscript 128 equals a

6
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1 mark

Solve the equation

2 to the power of x equals 16

7a
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2 marks

Solve the equation

x squared minus 12 x plus 27 equals 0

7b
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3 marks

Hence solve the equation

open parentheses 3 to the power of x close parentheses squared minus 12 open parentheses 3 to the power of x close parentheses plus 27 equals 0

8
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2 marks

Solve the equation

2 log subscript 3 space 9 equals 5 x minus 6

92 marks

Sketch the curve with equation

y equals straight e to the power of x

showing clearly any points of intersection with the coordinate axes.

On your sketch, state the equation of the asymptote.

10
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2 marks

A curve has the equation y equals straight e to the power of 2 x end exponent

(i) Write down an expression for fraction numerator straight d y over denominator straight d x end fraction

(ii) Find the gradient of the point on the curve where x equals 0

11
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2 marks

Find the values of

(i) space 5 space log subscript 3 space 7

(ii) space 2 space log subscript 2 space 3 plus 3 space log subscript 3 space 2

giving your answers to 4 significant figures.

12
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3 marks

Solve the equation

straight e to the power of 2 x end exponent minus 16 equals 0

giving your answer in the form

a ln a 

where a is an integer.

13
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4 marks

Write down the value of a in the following:

(i) space log subscript a 8 equals 3

(ii) space log a equals 2

(iii) space ln open parentheses straight e cubed close parentheses equals a

(iv) space log subscript 5 a equals 1

141 mark

The function straight f open parentheses x close parentheses is defined by

straight f open parentheses x close parentheses equals 3 straight e to the power of 2 x end exponent space space space space space space space space x element of straight real numbers

Find an expression for straight f open parentheses 2 x close parentheses.

151 mark

The function straight f open parentheses x close parentheses is defined by

straight f open parentheses x close parentheses equals 5 straight e to the power of 3 x end exponent space space space space space space space space x element of straight real numbers

Find an expression for straight f open parentheses 4 x close parentheses.

1a2 marks

Sketch the curve with equation

y equals 4 to the power of x

stating any points of intersection with the coordinate axes.

1b
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2 marks

Solve

4 to the power of x equals 100

giving your answer to 2 decimal places.

23 marks

On the same set of coordinate axes, sketch the curves

y equals 2 to the power of x

and

y equals 3 to the power of x

Label clearly

  • any points where the curves meet the coordinate axes

  • the equation(s) of any asymptotes

3a3 marks

Sketch the curve

y equals 1 over 2 to the power of x

State whether the graph shows exponential growth or exponential decay.

3b
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1 mark

Find the exact value of y spacewhen x equals 3.

4
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2 marks

Solve the equation

3 x plus 3 log subscript 2 4 equals 5 log subscript 6 216

53 marks

Use algebra to solve

2 to the power of 2 x end exponent minus 24 open parentheses 2 to the power of x close parentheses plus 128 equals 0

6a3 marks

On the same set of coordinate axes, sketch the curves

y equals straight e to the power of x

and

y equals straight e to the power of negative x end exponent

Label clearly

  • any points where the curves meet the coordinate axes

  • the equation(s) of any asymptotes

6b1 mark

Write down the gradient of the curve

y equals straight e to the power of x

at the point open parentheses 0 comma 1 close parentheses.

7a1 mark

Given that

y equals straight e to the power of 4 x end exponent

write down an expression for fraction numerator straight d y over denominator straight d x end fraction

7b1 mark

Given that

y equals 2 straight e to the power of 2 x end exponent

write down an expression for fraction numerator straight d y over denominator straight d x end fraction

7c
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3 marks

A curve has equation

y equals 3 straight e to the power of negative 2 x end exponent

Find the gradient of the point on the curve where x equals 3.

Give your answer in the form

p straight e to the power of q

where p and q are integers to be found.

8a2 marks

(i) Write down the gradient function of the curve y equals straight e to the power of negative 3 x end exponent

(ii) Find the gradient of the curve y equals straight e to the power of negative 3 x end exponent at the point where x equals 0

8b2 marks

(i) write down the exact gradient of the point on the curve y equals straight e to the power of negative 3 x end exponent where x equals 2

(ii) Find the x-coordinate of the point on the curve y equals straight e to the power of negative 3 x end exponent which has a gradient of negative 3 straight e to the power of negative 12 end exponent

9a3 marks

The function straight f open parentheses x close parentheses is defined by

straight f open parentheses x close parentheses equals 2 straight e to the power of 3 x end exponent space space space space space space space space x element of straight real numbers

(i) Write down the function straight f open parentheses negative x close parentheses.

(ii) On the same set of coordinate axes, sketch the curves of y equals straight f open parentheses x close parentheses and y equals straight f open parentheses negative x close parentheses.

Label any points where the graphs intersect the coordinate axes.

9b1 mark

A different function is given by

straight g open parentheses x close parentheses equals negative 2 straight e to the power of 3 x end exponent

State the single graph transformation that maps the curve y equals straight f open parentheses x close parentheses to the curve y equals straight g open parentheses x close parentheses.

10
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3 marks

Solve

straight e to the power of 2 x end exponent minus 8 straight e to the power of x plus 15 equals 0

giving your answer(s) to 3 significant figures.

11a3 marks

On the same set of coordinate axes, sketch the curves

y equals 4 to the power of x

and

y equals 5 to the power of x

Label clearly

  • any points where the curves meet the coordinate axes

  • the equation(s) of any asymptotes

11b1 mark

Write down an equation of the curve that is a reflection of y equals 4 to the power of x in the y-axis.

12a3 marks

(i) Sketch the curve with equation y equals 0.4 to the power of x

(ii) State whether the curve represents exponential growth or exponential decay.

12b1 mark

Find the value of x when y equals 0.064.

13a
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1 mark

Find the value of

log 1000 plus log 10000

13b
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1 mark

Solve

6 to the power of log subscript 6 space a end exponent equals 36

13c
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2 marks

Find the value of

fraction numerator 2 log subscript 4 64 plus 3 to the power of log subscript 2 8 end exponent minus log subscript 5 5 over denominator log 100 end fraction

14a3 marks

Sketch the curve with equation

y equals 12 straight e to the power of negative x end exponent space space space space space space space space space x greater or equal than 0

stating any points of intersection with the coordinate axes.

Write down the equations of any asymptotes.

14b1 mark

Find the gradient of the point on the curve y equals 12 straight e to the power of negative x end exponent where x equals 0.

15a
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2 marks

Solve

2 log 1000 equals x log subscript 16 4

15b
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2 marks

Solve

3 log subscript 4 x equals log subscript 4 x plus 3 log subscript 5 2 5

16a3 marks

On the same set of coordinate axes, sketch the curves

y equals 0.3 to the power of x

and

y equals 0.5 to the power of x

Label clearly

  • any points where the curves meet the coordinate axes

  • the equation(s) of any asymptotes

16b1 mark

Write down an equation of the curve that is a reflection of y equals 0.5 to the power of x in the y-axis.

17a3 marks

Sketch the curve

y equals 0.2 to the power of negative x end exponent

State

  • the equation of the asymptote

  • whether the graph shows exponential growth or exponential decay.

17b1 mark

Find the value of x when y equals 625.

18a3 marks

Sketch the curve with equation

y equals 4 straight e to the power of x space space space space space space space space space x greater or equal than 0

stating any points of intersection with the coordinate axes.

Write down the equations of any asymptotes.

18b
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2 marks

Find the gradient of the point on the curve y equals 4 straight e to the power of x where x equals 3.

Give your answer correct to 3 significant figures.

18c1 mark

The growth of a population, P, at time t years is modelled by the equation

P equals 4 straight e to the power of t


Write down the initial population.

19a2 marks

A curve has equation

y equals a straight e to the power of b x end exponent

where and a and b are non-zero constants.

At the point open parentheses 0 comma space a close parentheses, the gradient of the curve is 12.

Find an expression for b spacein terms of a.

19b1 mark

Hence write down the equation of the curve in terms of a and x only.

1a1 mark

The function straight g is defined by

straight g open parentheses x close parentheses equals fraction numerator 3 ln open parentheses x close parentheses minus 7 over denominator ln open parentheses x close parentheses minus 2 end fraction space space space space space space space space space space x greater than 0 space space space space space space space space space space x not equal to k

where k is a constant.

Deduce the value of k.

1b2 marks

Find the range of values of a for which

straight g left parenthesis a right parenthesis greater than 0

2
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3 marks

Solve

2 straight e to the power of 2 x end exponent equals straight e to the power of x plus 10

giving your answer(s) to 3 significant figures.

33 marks

Solve

2 open parentheses 2 to the power of 2 x end exponent close parentheses plus 4 equals 9 open parentheses 2 to the power of x close parentheses

4a2 marks

Show that the equation

straight e to the power of x minus straight e to the power of negative x end exponent equals 0

has only one real solution, which you should find.

4b2 marks

Show that the equation

straight e to the power of x plus straight e to the power of negative x end exponent equals 0

has no real solutions.

5
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3 marks

Without using a calculator, find the value of

fraction numerator 3 log subscript 6 216 minus ln open parentheses straight e to the power of 5 close parentheses plus 4 to the power of log subscript 5 625 end exponent over denominator log 10000 end fraction

Show the steps in your solution clearly.

64 marks

Solve

3 to the power of 2 open parentheses x plus 1 close parentheses end exponent plus 3 equals 28 open parentheses 3 to the power of x close parentheses

73 marks

Find two values of x for which

log open parentheses x squared close parentheses equals open parentheses log space x close parentheses squared

is true.

8a1 mark

A curve has equation

y equals 1 over a straight e to the power of negative b x end exponent

where a and b are non-zero constants.

State a condition on b to ensure the curve represents exponential decay.

8b
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2 marks

At the point open parentheses 0 comma space a close parentheses on the curve, the gradient is 10.

Use this information to find an expression for y in terms of a and x only.

9a1 mark

A particle is travelling with velocity v ms-1 at time t seconds.

The velocity of the particle is modelled by

v equals 0.3 straight e to the power of k t end exponent

where k is a constant.

Write down the initial velocity of the particle.

9b
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2 marks

Find an expression in terms of k and t for the acceleration of the particle.

9c
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2 marks

After 12 seconds, the velocity of the particle is 0.9 ms-1.

Find the value of k, giving your answer to 3 significant figures.

9d1 mark

State a problem with the model for large values of t.

10
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5 marks

Solve the equation

2 straight e to the power of 3 x end exponent minus 11 straight e to the power of 2 x end exponent plus 12 straight e to the power of x equals 0

giving your answer(s) to 3 significant figures.