# NCERT Class 11-Math's: Chapter –3 Trigonometric Functions Part 14

Get top class preparation for IMO Class-11 right from your home: fully solved questions with step-by-step explanation- practice your way to success.

Download PDF of This Page (Size: 146K) ↧

**Question 23:**

If has α and β as its roots, then prove that

**Answer:**

Given,

a d α and β are the roots of the equation.

Using the formula of multiple angles, we know that –

and

Clearly it is a quadratic equation in and as and are its solutions.

and are the roots of this quadratic equation.

We know that sum of roots of a quadratic equation:

Hence,

**Question 24:**

If then show that

**Answer:**

Given,

To prove:

Thus,

**Question 25:**

If lies in the first quadrant and then find the value of

**Answer:**

**Question 26:**

Find the value of the expression

**Answer:**

**Question 27:**

Find the general solution of the equation

**Answer:**

**Question 28:**

Find the general solution of the equation

**Answer:**

**Question 29:**

Find the general solution of the equation

**Answer:**