Question #59822

1 Answer
Oct 11, 2017

For -pi <= x <= pi:

x = -2.35619449, 2.35619449

Explanation:

2cos(x/3) - sqrt(2) = 0

2cos(x/3) = sqrt(2)

cos(x/3) = sqrt(2)/2

x/3 = cos^-1(sqrt(2)/2)

x = 3 * cos^-1(sqrt(2)/2)

The graph below represents y = 2cos(x/3) and y = sqrt(2)

www.desmos.com