Question

cos(3x)+0.5=0 how many solutions are there.

Answer 1

@satellite73 can u help me?

Answer 2

@zarkon can u help me?

Answer 3

there are an infinite number of solutions because cosine is periodic.
start with
\[\cos(3x)=-\frac{1}{2}\] making
\[3x=\frac{\pi}{3}+2k\pi\] or
\[3x=\frac{2\pi}{3}2k\pi\] and then divide by 3 to solve for x