3.5 The unit circle and exact valuesIB Maths: Analysis and Approaches HL: Subtopic test
10 questions, 27 marks
IB Maths: Analysis and Approaches HL
3.5 The unit circle and exact values
Total 27 marks
Name
Class
Date
- 1The point lies on the unit circle such that the line , where is the origin, makes an angle of measured anticlockwise from the positive -axis.(a)Write down the exact coordinates of .[1 mark]
- A
- B
- C
- D
(b)Find the equation of the line .[1 mark]- A
- B
- C
- D
(c)The point lies on the unit circle such that makes an angle of with the positive -axis. Find the exact distance .[2 marks]Total for question 1: 4 marks
- 2The angle satisfies , with and .(a)Find in terms of or .[1 mark]
- A
- B
- C
- D
(b)Find in terms of or .[1 mark]- A
- B
- C
- D
(c)Find in terms of and .[2 marks]Total for question 2: 4 marks
- 3In triangle , cm, cm and . There are two possible triangles that fit this information.(a)Using a calculator, find the two possible sizes of , and verify that both give a valid triangle.[3 marks](b)Let cm. By using the cosine rule in triangle , show that . Hence find the exact difference between the two possible lengths of .[4 marks]
Total for question 3: 7 marks
- 4A Ferris wheel has radius 20 m and its centre is 22 m above the ground. A seat starts level with the centre, on the right-hand side, and the wheel turns anticlockwise. After the wheel has turned through an angle radians, the seat is m to the right of the centre and its height above the ground is m. (A negative horizontal value means the seat is to the left of the centre.)(a)(i) Find the exact height of the seat when .[6 marks]
(ii) Find the exact horizontal distance of the seat from the centre when , and state whether it is to the left or right of the centre.
(iii) Find the values of , for , at which the seat is 32 m above the ground.(b)(i) Two seats are fixed at diametrically opposite points of the wheel. Show that the sum of their heights is always 44 m.[6 marks]
(ii) A seat is m above the ground and to the left of the centre. Find the value of , where , for this seat, justifying your answer.Total for question 4: 12 marks
End of questions