Question

cos^4 A- sin^4 A = 2 sin A- 1
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Answer 1

Answer:

i hope you are satisfied with my solution

Step-by-step explanation:

cos^4A- sin^4A

( cos^2A )^2 - (sin^2A)^2

( cos^2A - sin^2A )( cos^2A+ sin^2A )

(1- sin^2A - sin^2A)x 1

1 -2 sin^2A