Answer :

To Prove:

Formulas to use for proof:

Proof:

L.H.S = sin 3 x + sin 2 x - sin x

= (sin 3 x - sin x) + sin 2 x

Applying the formula of sin x - sin y= 2 cos 2x sin x + 2 sin x cos x [∵ sin 2x = 2 sin x cos x]

= 2 sin x (cos 2x + cos x)

= R.H.S

Hence, L.H.S = R.H.S…**Proved**

Rate this question :

If , find the value of .

RS Aggarwal - MathematicsFind the length of an arc of a circle of radius 14 cm which subtends an angle of 36^{0} at the centre

Express each of the following angles in radians

36°

RS Aggarwal - Mathematics

Using a protractor, draw each of the following angles.

-40°

RS Aggarwal - Mathematics

Using a protractor, draw each of the following angles.

430°

RS Aggarwal - Mathematics

Express each of the following angles in radians

-22°30’

RS Aggarwal - Mathematics

Express each of the following angles in radians

400°

RS Aggarwal - Mathematics

Express each of the following angles in radians

225°

RS Aggarwal - Mathematics

Using a protractor, draw each of the following angles.

300°

RS Aggarwal - Mathematics

The value of is

Mathematics - Exemplar