Question

cosA^6 + sinA^6 = 1 - 3sin^2A cos^2A
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Answer 1

LHS

(cos²A)³ + (sin²A)³

by using formula

a³+b³ = (a+b)(a²+b² - ab)

= (cos²A +sin²A)(cos^4 A+sin^4 A - cos²A sin²A)

by using formula

a²+b² = (a+b)²-2ab

= cos²A+sin²A -2cos²Asin²A - cos²Asin²A

= 1-3 sin²Acos²A

= RHS

Hence proved

Answer 2

Answer:

your answer attached in the photo