Prove that cos 2x cos "" x/2 -cos 3x ...

Prove that
` cos 2x cos "" x/2 -cos 3x cos " (9x)/(2) = sin 5x sin ""(5x)/(2).`

Verified by Experts

The correct Answer is:

`sin " (5x)/(2)=R.H.S.`

TRIGONOMETRIC FUNCTIONS
NCERT BANGLISH|Exercise EXERCISE 3.1|7 Videos
TRIGONOMETRIC FUNCTIONS
NCERT BANGLISH|Exercise EXERCISE 3.2|10 Videos
STRAIGHT LINES
NCERT BANGLISH|Exercise Miscellaneous Exercise on Chapter 10|24 Videos

Similar Questions

Explore conceptually related problems

cos ^(2) 2x -cos ^(2) 6x = sin 4x sin 8x

Prove that sin 5 x cos 2x + cos 6 x sin 3 x = sin 8x cos x

Evaluate int sin x cos x cos2x cos 4x cos 8x dx

Prove that, int(cos 5x + cos4x)/(1-2cos 3x)dx= -(1/2 sin2x + sinx)+c

Prove that (cos 7x+cos 5x)/(sin7x-sin 5x)=cotx

Prove that = (sin 5x - 2 sin 3 x + sin x)/( cos 5x - cos x) = tan x

If k is a positive integer, show that 2[ cos x+ cos 3x+ cos 5x+ ..+ cos (2k-1)x] = (sin 2kx)/(sin x)

Prove that (cos 7x + cos 5x)/( sin 7x - sin 5x) = cot x

Prove : int cos x cos 2 x cos 3 x dx = 1/4 ( x+ (sin 2x)/2 + (sin 4x)/4 + (sin6x)/6 ) + c

(cos 4x +cos 3x + cos 2x )/( sin 4x + sin 3x + sin 2x)= cot 3x