# Lecture - 12 Chapter 3 Trigonometric Functions

Introduction to Trigonometry Equations

Derivation of general solutions for zeroes trigonometry equations

Derivation of general solutions for non zeroes trigonometry equations

General Solutions and Principal Solutions

NCERT Exercise 3.4

Find the principal and general solutions of the following equations:

Question 1 $$\tan x = \sqrt{3}$$

Question 2 $$\sec x = 2$$

Question 3 $$\cot x = -\sqrt{3}$$

Question 4 $$\cosec x = -2$$

Example 22 Solve $$\tan 2x = – \cot \left ( x + \frac{\pi}{3} \right )$$.

## Clip - 1

Question 5 $$\cos 4x = \cos 2x$$

Question 6 $$\cos 3x + \cos x – \cos 2x = 0$$

Question 7 $$\sin 2x + \cos x = 0$$

Question 8 $$\sec^2 2x = 1 – \tan 2x$$

Question 9 $$\sin x + \sin 3x + \sin 5x = 0$$

Example 24 Solve $$2 \cos^2 x + 3 \sin x = 0$$