Radian Measure (Edexcel A Level Maths: Pure): Exam Questions

4 hours50 questions
1a1 mark
Sector of a circle with centre O, angle 40 degrees, radius 5 cm. Points A and B on the circumference define the arc of the sector.
Figure 1

Figure 1 shows a sector A O B of a circle with centre O, radius 5 cm and angle A O B equals 40 degree.

The attempt of a student to find the area of the sector is shown below.

table row cell Area space of space sector space end cell equals cell fraction numerator space 1 over denominator 2 end fraction r squared theta end cell row blank equals cell 1 half cross times 5 squared cross times 40 end cell row blank equals cell 500 space cm squared end cell end table

Explain the error made by this student.

1b
Sme Calculator
2 marks

Write out a correct solution.

Did this page help you?

2
Sme Calculator
5 marks

Without using a calculator, write down:

(i) 60° in radians,

(ii) sin 45 degree

(iii) tan straight pi

(iv) fraction numerator 5 straight pi over denominator 6 end fraction radians in degrees

(v) cos 0

Did this page help you?

3
Sme Calculator
4 marks

A sector of a circle,O P Q , is such that it has radius 4 cm and the angle at its centre, O, is straight pi over 4 radians.

(i) Find the length of the arc P Q.

(ii) Find the area of the sector O P Q.

Did this page help you?

4
Sme Calculator
4 marks

Given that theta is small, write an approximation, in terms of theta for

(i) sin theta pluscos theta

(ii) 2 tan2 thetaminuscos theta

Did this page help you?

5
Sme Calculator
3 marks

The sector of a circle is shown below.

q4-5-4-radian-measure-a-level-only-edexcel-a-level-pure-maths-easy

Find the perimeter of the sector.

Did this page help you?

6
Sme Calculator
3 marks

The area of a quarter circle is 18 straight pi cm2.

Find the radius of the circle.

Did this page help you?

7
Sme Calculator
4 marks

Find all the solutions to the equation 2 sin theta equals square root of 3 for   negative 2 straight pi less or equal than theta less or equal than 2 straight pi.

Did this page help you?

8
Sme Calculator
2 marks

The arc length of the sector of a circle is 5 cm.

The radius is twice the length of the arc.

Find the angle at the centre of the circle.

Did this page help you?

9a
Sme Calculator
2 marks

The diagram below shows the sector of a circle, O P Q, radius 6 cm and centre angle straight pi over 12 radians.

q8a-5-4-radian-measure-a-level-only-edexcel-a-level-pure-maths-easy

Use the formula 1 halfab sin C to find the area of the triangle O P Q.

9b
Sme Calculator
2 marks

Find the area of the sector O P Q.

9c
Sme Calculator
2 marks

Hence or otherwise find the area of the shaded segment.

Did this page help you?

10
Sme Calculator
4 marks

The area of a sector is 8 straight pi cm2.

The arc length of the sector is 4 straight pi cm.

Find the radius and the angle at the centre of the circle.

Did this page help you?

11
Sme Calculator
4 marks

Given that theta is small, show that sin 4 thetaalmost equal to 2 sin 2 theta cos 2 theta.

Did this page help you?

14 marks
Diagram of a sector of a circle with centre O, radius r, and angle θ. Points A and B are on the circle's edge, forming arc AB.
Figure 1

Figure 1 shows a sector A O B of a circle with centre O and radius r cm.

The angle A O B is theta radians.

The area of the sector A O B is 11 cm2.

Given that the perimeter of the sector is 4 times the length of the arc A B, find the exact value of r.

Did this page help you?

2a1 mark
Diagram of a sector OCD with centre O, radius 2r and angle θ. Two additional, congruent sectors OAB and OEF with centre O and radius r are located one on each side of sector OCD. AOF is the horizontal base of the logo.
Figure 1

The shape O A B C D E F O shown in Figure 1 is a design for a logo.

In the design

  • O A B is a sector of a circle centre and radius r

  • sector O F E is congruent to sector O A B

  • O D C is a sector of a circle centre O and radius 2 r

  • A O F is a straight line

Given that the size of angle C O D is theta radians, write down, in terms of theta, the size of angle A O B

2b2 marks

Show that the area of the logo is

1 half r squared open parentheses 3 theta plus pi close parentheses

2c2 marks

Find the perimeter of the logo, giving your answer in simplest form in terms of r, theta and pi.

Did this page help you?

3a
Sme Calculator
2 marks
Diagram of a stage with angle 2.3 rad at point O, arc DE is 27.6m, base AG is 15m. Note: Diagram not accurately drawn.
Figure 1

Figure 1 shows the plan view of a stage.

The plan view shows two congruent triangles A B O and G F O joined to a sector O C D E O of a circle, centre O, where

  • angle C O E equals 2.3 radians

  • arc length C D E equals 27.6 m

  • A O G is a straight line of length 15 m

Show that O C equals 12 m.

3b
Sme Calculator
2 marks

Show that the size of angle A O B is 0.421 radians correct to 3 decimal places.

3c
Sme Calculator
6 marks

Given that the total length of the front of the stage, B C D E F, is 35 m, find the total area of the stage, giving your answer to the nearest square metre.

Did this page help you?

43 marks

Given that theta is small and is measured in radians, use the small angle approximations to find an approximate value of

fraction numerator 1 minus cos 4 theta over denominator 2 theta sin 3 theta end fraction

Did this page help you?

53 marks

Given that theta is small and measured in radians, use the small angle approximations to show that

4 sin theta over 2 plus 3 cos squared theta almost equal to a plus b theta plus c theta squared

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

Did this page help you?

6
Sme Calculator
5 marks

Complete the table.

Degrees

Radians

sin

cos

tan

 

straight pi over 6

 

fraction numerator square root of 3 over denominator 2 end fraction

 

45 to the power of blank to the power of straight o end exponent

 

 

fraction numerator 1 over denominator square root of 2 end fraction

 

60 to the power of blank to the power of straight o end exponent

straight pi over 3

 

 

 

 

fraction numerator 2 straight pi over denominator 3 end fraction

fraction numerator square root of 3 over denominator 2 end fraction

 

 

270 to the power of blank to the power of straight o end exponent

 

 

 

bevelled n over a

Did this page help you?

7
Sme Calculator
4 marks

A sector of a circle,O P Q, is such that it has radius 3.4 cm and the angle at its centre, O, is fraction numerator 3 straight pi over denominator 4 end fraction radians.

(i) Find the length of the arc P Q.

(ii) Find the area of the sector O P Q.

Did this page help you?

8
Sme Calculator
3 marks

Given that theta is small, write an approximation in terms of theta for

                                             2sin thetapluscos theta minustan2 theta

Did this page help you?

9
Sme Calculator
5 marks

The sector of a circle is shown below.

q4-5-4-radian-measure-a-level-only-edexcel-a-level-pure-maths-medium

Find the area and the perimeter of the sector.

Did this page help you?

10
Sme Calculator
4 marks

A rainbow-shaped logo is formed from two semicircles as shown below.
The radius of the smaller semicircle is 1 cm less than the radius of the larger semicircle.

q5-5-4-radian-measure-a-level-only-edexcel-a-level-pure-maths-medium

Find the area of the logo.

Did this page help you?

11a
Sme Calculator
5 marks

The diagram below shows the sector of a circle O A B.

q6a-5-4-radian-measure-a-level-only-edexcel-a-level-pure-maths-medium

(i) Find the area of the sector O A B, giving your answer to 3 significant figures.

(ii) Find the area of the triangle O A B, giving your answer to 3 significant figures.

(iii) Find the area of the shaded segment, giving your answer to 3 significant figures.

11b
Sme Calculator
3 marks

(i) Find the length of the arc A B.

(ii) Find the perimeter of the sector O A B.

Did this page help you?

12
Sme Calculator
3 marks

The canopy of a parachute and the outermost connecting cords form a sector of a circle as shown in the diagram below, with the parachutist modelled as a particle at point O.

q7-5-4-radian-measure-a-level-only-edexcel-a-level-pure-maths-medium

The area of the sector O A B is  fraction numerator 81 straight pi over denominator 200 end fractionm2.

Find the length of one of the connecting cords on the parachute.

Did this page help you?

13a
Sme Calculator
3 marks

Given that x is small, show that 

16 minus 7 sin x plus 2 tan 2 xnegative 18 cos xalmost equal to 9 x squared minus 3 x minus 2

13b
Sme Calculator
3 marks

Hence, or otherwise, find approximate solution(s) to the equation

16 minus 7 sin x plus 2tan 2 x minus 18 cos x equals 0

Did this page help you?

14a
Sme Calculator
4 marks

Find all solutions to the equation cos theta equals 1 half  in the interval  negative 2 straight pi less or equal than theta less or equal than 2 straight pi , giving your answers in radians as multiples of straight pi.

14b
Sme Calculator
6 marks

Find all solutions to the equation 5 sin 3 x equals 1  in the interval 0 less or equal than space x less or equal than straight pi , giving your answer in radians to three significant figures.

Did this page help you?

15
Sme Calculator
3 marks

A plastic puzzle piece is in the form of a prism with a cross-section that is the sector of a circle, as shown in the diagram below.  The radius of the sector is 8 cm, and the angle at the centre is 1.2 radians.

The height of the puzzle piece is 2 cm.

q10-5-4-radian-measure-a-level-only-edexcel-a-level-pure-maths-medium

(i) Work out the area of the cross-section.

(ii) Hence, or otherwise, work out the volume of the puzzle piece.

Did this page help you?

16a
Sme Calculator
2 marks

The circle sector O A B is shown in the diagram below.

The angle at the centre is straight pi over 3 radians , and the line
segments O C and B C have lengths of 8 cm and pcm respectively.

Additionally, C D is parallel to A B, so that A D equals B C and O D equals O C.

q11a-5-4-radian-measure-a-level-only-edexcel-a-level-pure-maths-medium

Show that the area of the sector O A B is  straight pi over 6 open parentheses p plus 8 close parentheses squared cm2.

16b
Sme Calculator
2 marks

Show that the area of the triangle O C D is 16 square root of 3 cm2.

16c
Sme Calculator
4 marks

Given that the area of the shaded shape A B C D is open parentheses fraction numerator 50 straight pi over denominator 3 end fraction minus 16 square root of 3 close parentheses cm2.  find the value of p.

Did this page help you?

1
Sme Calculator
4 marks
Prism with a top face in the shape of a sector. The angle of the sector BAC is 0.8 radians, height h and radius r
Figure 5

A company makes toys for children.

Figure 5 shows the design for a solid toy that looks like a piece of cheese.

The toy is modelled so that

  • face A B C is a sector of a circle with radius r cm and centre A

  • angle B A C equals 0.8 radians

  • faces A B C and D E F are congruent

  • edges A D comma space C F and B E are perpendicular to faces A B C and D E F

  • edges A D comma space C F and B E have length h cm

Given that the volume of the toy is 240 space cm cubed show that the surface area of the toy, S space cm squared, is given by

S equals 0.8 r squared plus 1680 over r

making your method clear.

Did this page help you?

2
Sme Calculator
3 marks

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

Solutions relying entirely on calculator technology are not acceptable.

The curve C has equation y equals straight f left parenthesis x right parenthesis where x element of straight real numbers

Given that

  • straight f prime left parenthesis x right parenthesis equals 2 x plus 1 half cos space x

  • the curve has a stationary point with x coordinate alpha

  • alpha is small

use the small angle approximation for cos space x to estimate the value of alpha to 3 decimal places.

Did this page help you?

3a2 marks
Graph of y=cos(x) showing one complete cycle in both the positive and negative x-directions.
Figure 1

Figure 1 shows a plot of part of the curve with equation y equals cos space x where x is measured in radians.

Diagram 1, shown below, is a copy of Figure 1.

Use Diagram 1 to show why the equation

cos space x minus 2 x minus 1 half equals 0

has only one real root, giving a reason for your answer.

Graph of y=cos(x) showing one complete cycle in both the positive and negative x-directions.
Diagram 1
3b
Sme Calculator
3 marks

Given that the root of the equation is alpha, and that alpha is small, use the small angle approximation for cos space x to estimate the value of alpha to 3 decimal places.

Did this page help you?

4
Sme Calculator
4 marks

Complete the table.

Degrees

Radians

sin

cos

tan

 

straight pi over 6

 

fraction numerator square root of 3 over denominator 2 end fraction

 

135 to the power of blank to the power of straight o end exponent

 

fraction numerator 1 over denominator square root of 2 end fraction

 

 

180 to the power of blank to the power of straight o end exponent

 

 

 

0

 

 

negative 1 half

fraction numerator square root of 3 over denominator 2 end fraction

 

Did this page help you?

5
Sme Calculator
3 marks

Given that straight theta is small, write an approximation in terms of straight theta for

fraction numerator sin squared space theta plus cos space theta over denominator tan space theta plus sin space theta end fraction

Did this page help you?

6
Sme Calculator
4 marks

The canopy of a parachute and the outermost suspension lines (cords) form a sector of a circle as shown in the diagram below, with the parachutist modelled as a particle at point O.

q3-5-4-radian-measure-a-level-only-edexcel-a-level-pure-maths-hard

The area of the sector O A B is  fraction numerator 49 straight pi over denominator 150 end fraction m2.

The parachute is made with 40 equal length suspension lines.

Disregarding any additional lengths of cord that might be required for knots, fastenings, etc., find the total length of the suspension lines required to make the parachute.

Did this page help you?

7
Sme Calculator
4 marks

A sector of a circle,O P Q , is such that it has radius a cm and the angle at its centre, O, is a squared straight pi radians.

Given that the area of the sector O P Q in cm2 is three times the length of the arc P Q in cm, find the value of a.

Did this page help you?

8a
Sme Calculator
5 marks

The diagram below shows the sector of a circle O A B.

q5a-5-4-radian-measure-a-level-only-edexcel-a-level-pure-maths-hard

Given that the area of triangle O A Bequals 5.64 cm2, find the area of the shaded segment. Give your answer correct to 3 significant figures.

8b
Sme Calculator
3 marks

Find the perimeter of the sector O A B, giving your answer correct to 3 significant figures.

Did this page help you?

9a
Sme Calculator
4 marks

When x is small, show that the equation

cos2 3 x plus 1 fourth tan4 3 x equals 1

can be written as

81 over 2 x to the power of 4 minus 9 x squared equals 0

9b
Sme Calculator
3 marks

Hence find approximate solutions to the equation

cos2 3 x plus 1 fourthtan4 3 x equals 1

9c
Sme Calculator
2 marks

Comment on the validity of your solutions.

Did this page help you?

10a
Sme Calculator
4 marks

The circle sector O A B is shown in the diagram below.

The angle at the centre is theta radians , and the radii O A and O B are each equal to r cm

Additionally,C D is parallel to A B, so that  A D equals B C and O D equals O C.

q7a-5-4-radian-measure-a-level-only-edexcel-a-level-pure-maths-hard

In the case when A D equals B C equals 1 cm, show that the area of the shaded shape A B C D is given by 1 half straight theta r squared minus 1 half open parentheses straight r minus 1 close parentheses squared sin theta.

.

10b
Sme Calculator
3 marks

Show that for small values of theta, the area of A B C D is approximately 1 half theta open parentheses 2 straight r minus 1 close parentheses.

Did this page help you?

11
Sme Calculator
5 marks
q8a-5-4-radian-measure-a-level-only-edexcel-a-level-pure-maths-hard

The diagram shows a prism with cross-section in the shape of a sector of a circle. 

The radius of the sector is open parentheses 2 a minus 3 close parentheses cm, and the angle at the centre is 1.7 radians.

The height of the prism is 4 cm.

Given that the volume of the prism is 7.65 cm3, find the possible value(s) of a.

Did this page help you?

12
Sme Calculator
5 marks

A rainbow-shaped logo is formed from three semicircles as shown below.
Each of the inner semicircles has a radius that is 1 cm less than that of the next semicircle further out.

q9-5-4-radian-measure-a-level-only-edexcel-a-level-pure-maths-hard

Find, in simplest terms, the ratio of the outer area A of the logo, to the inner area B

Did this page help you?

13a
Sme Calculator
4 marks

Find all the solutions to the equation square root of 3 tan 2 theta equals negative 1 in the interval  negative straight pi less or equal than theta less or equal than straight pi, giving your answers in radians as multiples of straight pi .

13b
Sme Calculator
5 marks

Find all the solutions to the equation 6 sin2 xplus 7 sin x minus 3 equals 0  in the interval   0 less or equal than space x less or equal than 2 straight pi  ,  giving your answers in radians to three significant figures.

Did this page help you?

1a
Sme Calculator
4 marks
Two intersecting circles, C1 and C2, on x and y axes. Circle C1 is larger, centred at the origin. Circle C2 has its centre on the positive x axis. Circle C2 intersects C1 at points A and B which have positive x values.
Figure 3

Circle C subscript 1 has equation x squared plus y squared equals 100.

Circle C subscript 2 has equation open parentheses x minus 15 close parentheses squared plus y squared equals 40.

The circles meet at points A and B as shown in Figure 3.

Show that angle A O B=0.635 radians to 3 significant figures, where O is the origin.

1b
Sme Calculator
4 marks

The region shown shaded in Figure 3 is bounded by C subscript 1 and C subscript 2

Find the perimeter of the shaded region, giving your answer to one decimal place.

Did this page help you?

2
Sme Calculator
3 marks

Complete the table.

Degrees

Radians

sin

cos

tan

45 to the power of blank to the power of straight o end exponent

straight pi over 4

 

 

 

150 to the power of blank to the power of straight o end exponent

 

1 half

 

 

 

fraction numerator 7 straight pi over denominator 4 end fraction

 

 

negative 1

Did this page help you?

3
Sme Calculator
3 marks

Given that theta is small, find an approximate expression in terms of straight theta for

fraction numerator sin squared space theta plus 2 space cos squared space 2 theta minus tan space 3 theta over denominator sin space 4 theta end fraction

Did this page help you?

4
Sme Calculator
5 marks

The canopy of a parachute and the outermost suspension lines (cords) form a sector of a circle as shown in the diagram below, with the parachutist modelled as a particle at point O

q3-5-4-radian-measure-a-level-only-edexcel-a-level-pure-maths-veryhard

The area of the sector O A B is   fraction numerator 125 straight pi over denominator 144 end fraction m2  .

The length of the arc A B is  fraction numerator 25 straight pi over denominator 36 end fraction m .

Find the length of one suspension line and the angle A O B that the parachutist makes with the two outermost suspension lines.

Did this page help you?

5a
Sme Calculator
7 marks

Given that theta is small, find approximate solution(s) to the equation

fraction numerator 4 space cos squared space 4 theta minus sin open parentheses 2 theta close parentheses squared over denominator tan squared space theta end fraction equals 12

5b
Sme Calculator
2 marks

Comment on the relative reliability of the solution(s) you found in part (a).

Did this page help you?

6a
Sme Calculator
3 marks

The diagram below shows the sector of a circle O A B.

q5a-5-4-radian-measure-a-level-only-edexcel-a-level-pure-maths-veryhard

Show that the area of the shaded segment is given by  1 half r squared open parentheses theta minus sin space theta close parentheses cm2.

6b
Sme Calculator
2 marks

Find, in terms of theta, the percentage of the sector that the segment occupies.

Did this page help you?

7
Sme Calculator
7 marks

An evil wizard has captured a unicorn, and is threatening to kill it unless you can answer the following question:

“I wish to create a rainbow-shaped mosaic for the floor of the throne room in my castle. 

 The mosaic is to be formed from four semicircles as shown below.

The innermost semicircle is to have a radius of R metres, and each of the outer semicircles must have a radius that is a constant k metres greater than the radius of the next semicircle further in.

 The rainbow mosaic must be exactly 22 metres across.

q6-5-4-radian-measure-a-level-only-edexcel-a-level-pure-maths-veryhard

Moreover, I wish the inner part of the area (labelled  in the diagram) to take up exactly one quarter of the total area of the rainbow.

Find me the required values of R and k, or the unicorn dies.  Bwah-ha-ha-ha-ha!”

Solve the wizard’s problem and save the unicorn.

Did this page help you?

8a
Sme Calculator
2 marks

A sector of a circle, O S T, is such that it has radius r cm  and the angle at its centre,O , is theta radians.  The chord S T has length a cm.

Show that  a squared equals 2 r squared open parentheses 1 minus cos space theta close parentheses.

8b
Sme Calculator
5 marks

Given that r equals 4 theta  and that the area of the sector is  fraction numerator 8 straight pi cubed over denominator 27 end fraction cm2 , find the value of a.

Did this page help you?

9a
Sme Calculator
6 marks

Find all the solutions to the equation 2 cos 2 theta equals 4 sin 2 theta cos 2 theta  in the interval   0 less or equal than theta less or equal than 2 straight pi   , giving your answers in radians as multiples of straight pi.

9b
Sme Calculator
6 marks

Find all the solutions to the equation  3 cos2 4 x plus 13 cos 4 x minus 10 equals 0  in the interval 0 less or equal than x less or equal than straight pi, giving your answers in radians to three significant figures.

Did this page help you?

10
Sme Calculator
6 marks

The diagram below shows the sector of a circle with centre O.  The radii O A and O B are each equal to r cm, and the angle at the centre,A O B , is equal to straight theta radians.  The line D C is perpendicular to the line O B.

q9-5-4-radian-measure-a-level-only-edexcel-a-level-pure-maths-veryhard

Given that  B Ccolon C O equals 2 colon 3, show that the area of the shaded shape A B C D is given by

1 over 50 r squared open parentheses 25 straight theta minus 9 space tan space theta close parenthesescm2.                          

Did this page help you?