Question

How do you find `\cos ( \frac { 1} { 2} x ) + 1= 0`?

Answer 1

`x=2pi+4kpi`

Explanation:

`cos(1/2x)+1=0`
`cos(1/2x)=-1`

`cos()` function has value "-1" at: `pi+2kpi`

SO ..

`1/2x=pi+2kpi`

`x=2pi+4kpi` where `k in CC`