Question

Prove that : cosx^4- cosx^2 = sin^4, - sin^2​

Answer 1

Answer:

Proved

Step-by-step explanation:

(cos²x)² - cos²x

As sin²x + cos²x = 1,

⇒ (1-sin²x)² - (1 - sin²x)

⇒ 1 - 2sin²x + (sin²x)² - 1 + sin²x

⇒ $sin^{4} x - sin^{2} x$

Hence Proved.

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