cos6x = 4 cos32x - 3 cos2x = 4(2cos2x-1)3 - 3(2cos2x-1) = 4[(2cos2x)3 - 3×(2cos2x)2×1 + 3 × 2 cos2x×1 - 13]-6cos2x + 3 = 32cos6x - 48cos4x + 18cos2x -1 = R.H.S Hence proved

Q. 355.0( 2 Votes )

Prove th

Class 11th

Answer :

cos6x  = 4 cos³2x - 3 cos2x

          = 4(2cos²x-1)³ - 3(2cos²x-1)

          = 4[(2cos²x)³ - 3×(2cos²x)²×1 + 3 × 2 cos²x×1 - 1³]-6cos²x + 3

          = 32cos⁶x - 48cos⁴x + 18cos²x -1

          = R.H.S

Hence proved

Rate this question :

How useful is this solution?

We strive to provide quality solutions. Please rate us to serve you better.

PREVIOUS Prove th

Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts

Dedicated counsellor for each student

24X7 Doubt Resolution

Daily Report Card

Detailed Performance Evaluation

view all courses