Exercise 4.2: Cosine Function and Inverse Cosine Function

EXERCISE 4.2

1. Find all values of x such that

(i) -6π ≤ x ≤ 6π and cos x = 0 (ii) -5π ≤ x ≤ 5π and cos x = 1.

2. State the reason for 

3. Is cos−1 (−x) = p −cos−1 (x) true? Justify your answer.

4. Find the principal value of cos−1 (1/2)

5. Find the value of

6.Find the domain of 

7. For what value of x , the inequality π/2 < cos-1 (3x -1) < π holds?

8. Find the value of 

Answers: