Right, im confused by this question...

Findallthe roots in the range -2π < x < 2π of the equation cos(2x) = 0.5 giving all the answers in radians as multiples of π.

At first i thought it would be a (varying) cosine wave but how does that make sense, where is the 'y'? I thought by 'find the roots' it meant finding the angles at which the wave goes through the x axis between that range...

any help. please? this is the last question and its in for tomorra