One root of the equation `cos x-x+1/2=0` lies in the interval (A) `[0, – InterviewSolution

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1.	One root of the equation `cos x-x+1/2=0` lies in the interval (A) `[0,pi/2]` (B) `[-pi/2,0]` (C) `[pi/2,0]` (D) noneA. `(0, pi/2)`B. `(- pi/2, 0)`C. `(pi/2, pi)`D. `(pi, (3pi)/2)`
Answer» Correct Answer - A Let `f(x)=cos x-x+1/2` `f(0)=1+1/2 gt 0` `f(pi/2)=0- pi/2 + 1/2=(1-pi)/2 lt 0` Therefore, one root lies in the interval `(0, pi/2)`.

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