Question

How do you solve `2(cosx+1)=1` in the interval `0<=x<=2pi`?

Answer 1

In the interval `0<=x<=2pi ,x= (2pi)/3 and x= (4pi)/3`

Explanation:

`2(cosx+1)=1 or (cosx+1)=1/2 or cosx= -1/2`

In the interval `0<=x<=2pi , cos (pi-pi/3) = -1/2 and cos (pi+pi/3) = -1/2`

Solution : `x= (2pi)/3 and x= (4pi)/3` [Ans]