If tan α=2,then the values of x which satisfy the relation
tanx=12are 0<x<2π and 0<α<π2
π2−α
We have tan α=2
⇒cotα=12
So, we are given tanx=12=cot α or tanx=cotα
We know tan π2−α=tan(3π2−α)=cotα
⇒tanx=tan(π2−α)or tan(3π2−α)
⇒x=π2−αorx=3π2−α
We considered on π2 - α and 3π2−αbecause we want 0<x<2π