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Cos^4x - sin^4x = a. Cos^4x
b. Cos^2x
c. –sinx
d. Sin^2x
i think the answer should be either (1-2sin^2x) or (2cos^2x)....confused!?
Science & Mathematics by Anonymous 2018-07-13 11:04:39
Social Science
Cos^4x - sin^4x = a. Cos^4x b. Cos^2x c. –sinx d. Sin^2x i think the answer should be either (1-2sin^2x) or (2cos^2x)....confused!?
2 answers
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Anonymous
[ cos ²x - sin²x ] [ cos²x + sin²x ] = cos 2x
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Anonymous
cos^4(x)-sin^4(x)=[cos^2(x)+sin^2(x)][co... which is the answer. Also, 1-2sin^2(x) or 2cos^2(x)-1 is true.