Math, asked by somwriksinha, 9 months ago

prove that cos^2 2x = 1/2(1 + cos 4x)​

Answers

Answered by raviparmar2002
1

Step-by-step explanation:

cos4x

= cos (2x + 2x)

= cos 2x cos 2x - sin 2x sin 2x

= cos²2x - sin²2x

= cos²2x - 1 + cos²2x

= 2cos²2x - 1

Thus cos²2x = ½ ( 1 + cos4x )

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