Question

Prove it...
please prove the question step by step​

Answer 1

cos6x = 32cos⁶x - 48 cos⁴x + 18 cos²x - 1

LHS ↓

cos6x = cos(2×3x)

• cos2x = 2cos²x - 1

cos6x = 2cos²(3x) −1

cos6x = 2 (cos 3x)² − 1

• cos3x = 4cos³x − 3cosx

cos6x = 2 (4cos³x − 3cosx)² –1

cos6x = 2(16cos⁶x – 24cos⁴x + 9cos²x) – 1

cos6x = 32cos⁶x −48cos⁴x + 18cos²x – 1

RHS ↑

LHS = RHS

______HENCE PROVED

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