A) \[4\pi \]
B) \[5\pi \]
C) \[7\pi \]
D) \[8\pi \]
Correct Answer: C
Solution :
\[\cos 2x(1-\cos 2x)=0\] \[\cos 2x=1\] or \[\cos 2x=0\] \[\therefore \]\[x=n\pi \] or \[x=(2n-1)\frac{\pi }{4}\] \[0,\,\,\pi ,\,\,2\pi \] or \[\frac{\pi }{4},\,\,\frac{3\pi }{4},\,\,\frac{5\pi }{4},\,\,\frac{7\pi }{4}=7\pi \]You need to login to perform this action.
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