Find all values of that satisfy in the interval .

MATHEMATICS · Single correct · AP · AP Precalculus · Trigonometric and Polar Functions · Trigonometric and Polar Functions

Problem

Find all values of

x

that satisfy

\cos x = -\dfrac{1}{2}

in the interval

0 \le x < 2\pi

. (a)

\left\{\dfrac{5\pi}{6},\,\dfrac{11\pi}{6}\right\}

(b)

\left\{\dfrac{2\pi}{3},\,\dfrac{4\pi}{3}\right\}

(c)

\left\{\dfrac{\pi}{3},\,\dfrac{5\pi}{3}\right\}

(d)

\left\{\dfrac{7\pi}{6},\,\dfrac{11\pi}{6}\right\}