Find the values of theta between 0 degrees and 360 degrees which satisfy the equations cos 3 theta = 1/2 - Maths - Trigonometric Functions

Question

Find the values of theta between 0 degrees and 360 degrees which
satisfy the equations cos 3 theta = 1/2?

Ajanta Trivedi · Accepted Answer

the given trigonometric equation is
cos3θ=12
cos3θ=cos60⇒3θ=2nπ±60⇒θ=2nπ3±20if n=0⇒θ=20 [as θ>0if n=1;θ=2*1803±20θ=120±20⇒θ=100 or 140if n=2;θ=2*2*1803±20θ=240±20⇒θ=220 or 260if n=3;θ=2*3*1803±20θ=360±20⇒θ=340 [as <360
thus the possible values of
θ are 20,100,140,220,260,340

hope this helps you

Find the values of theta between 0 degrees and 360 degrees which satisfy the equations cos 3 theta = 1/2?