Question

please answer it fast it's needed
class 11 ch-3 (TRIGONOMETRY)​

Answer 1

solving L. H. S

using a²+b²=(a+b) (a-b)

(sin 6x+ sin 4x) (sin 6x - sin 4x)

let's calculate both of them separately

(sin 6x+ sin 4x)

using sin x + sin y= 2 sin x+y/2 cos x-y/2

2 sin (6x+4x/2) cos 6x-4x/2

2sin (10 x/2) cos (2x/2)

2sin 5x cos x

(sin 6x-sin 4x)

using sin x-sin y=2 cos x+y/2 sin x-y /2

2 cos (6x+4x/2) sin ( 6x -4x /2)

2cos( 10x/2) sin (2x/2)

2cos 5x sin x

Hope it will help you