**Question 1.Find the principal values of the following :**

**Question 2.Evaluate the following :Solution:**

**Solution:**

**(iii) tan ^{-1}√3 – sec^{-1}(-2)**

Solution:

**(iv) cosec ^{-1}(−√2) + cot^{-1}(√3)**

Solution:

**Question 3.Prove the following :Solution:**

Solution:

Solution:

Solution:

**Solution:**

= θ/2 …[∵ tan^{-1}(tanθ) = θ]

= RHS.