Use a calculator to solve the equation on the interval [0, 2π). Round the answer to two decimal places.
-$\cos 3 x = - \cos x$
A) $0.79,1.57,2.36,3.93,4.71,5.50$
B) $0,0.79,2.36,3.14,3.93,5.50$
C) $0,1.57,3.14,4.71$
D) $1.57,4.71$

Question

Quizplus · Accepted Answer

The equation $\cos 3x = -\cos x$ can be solved by using trigonometric identities or graphically. By graphing or solving, we find that the solutions within the interval [0, 2π) are approximately $0.79, 1.57, 2.36, 3.93, 4.71,$ and $5.50$ radians, which matches option A.

Use a Calculator to Solve the Equation on the Interval cos⁡3x=−cos⁡x\cos 3 x = - \cos xcos3x=−cosx

Use a Calculator to Solve the Equation on the Interval $\cos 3 x = - \cos x$