cmi-entrance 2010 Q1

cmi-entrance · India · ugmath 4 marks Standard trigonometric equations Solve trigonometric equation for solutions in an interval

Find all $x \in [ - \pi , \pi ]$ such that $\cos 3 x + \cos x = 0$.

Find all $x \in [ - \pi , \pi ]$ such that $\cos 3 x + \cos x = 0$.