Let for . The derivative equals at a single point in this interval. Which of the…

MATHEMATICS · Single correct · A Level · Mathematics · Differentiation · Differentiation

Problem

Let

F(x)=\sec x - x

for

0<x<\dfrac{\pi}{2}

. The derivative

F'(x)

equals

0

at a single point in this interval. Which of the following values is closest to that

x

-coordinate? (a)

\dfrac{\pi}{4}

(b)

\dfrac{2\pi}{9}

(c)

\dfrac{\pi}{8}

(d)

\dfrac{\pi}{6}