A) 0
B) -1
C) 2
D) 1
Correct Answer: D
Solution :
We have \[\sin x+{{\sin }^{2}}x=1\,\,\Rightarrow \,\,\sin x={{\cos }^{2}}x\] \ \[{{\cos }^{8}}x+2{{\cos }^{6}}x+{{\cos }^{4}}x={{\sin }^{4}}x+2{{\sin }^{3}}x+{{\sin }^{2}}x\] \[={{(\sin x+{{\sin }^{2}}x)}^{2}}=1\].You need to login to perform this action.
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