Question

Prove that 32cosh⁶x = cosh6x + 6cosh4x + 15cosh2x +10 ​

Answer 1

Answer:

LHS = cos3(2x)  = 4cos32x - 3cos2x  = 4(2cos2x - 1)3  – 3(2cos2x -1)  = 4[8cos6x -1 – 3(2cos2x)(2cos2x - 1)] - 6cos2x + 3  = 32cos6x - 4 - 24cos2x(2cos2x - 1) - 6cos2x + 3  = 32cos6x – 48cos4x +18cos2 x - 1 = RHS.Read more on Sarthaks.com - https://www.sarthaks.com/585165/prove-that-cos6x-32cos-6x-48cos-4x-18cos-2x-1