A) \[\left[ 0,\,\frac{\pi }{2} \right]\]
B) \[\left[ -\frac{\pi }{2},\,0 \right]\]
C) \[\left[ \frac{\pi }{2},\,\pi \right]\]
D) \[\left[ \pi ,\frac{3\pi }{2} \right]\]
Correct Answer: A
Solution :
\[f(x)=\cos x-x+\frac{1}{2}\], \[f(0)=\frac{3}{2}>0\] \[f\left( \frac{\pi }{2} \right)=0-\frac{\pi }{2}+\frac{1}{2}=\frac{1-\pi }{2}<0\], \[\left( \because \ \pi =\frac{22}{7}\text{ nearly} \right)\] \ One root lies in the interval\[\left[ 0,\,\frac{\pi }{2} \right]\].You need to login to perform this action.
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