how do i solve this? can i have an explanation too if possible?

Answer:
x = 120
Step-by-step explanation:
First you want to get the equation into the form cosx = a
2 cos[tex]\frac{x}{2}[/tex]=1
Divide both sides by two to get it into the form.
cos[tex]\frac{x}{2}[/tex]= [tex]\frac{1}{2}[/tex]
Now, on your calculator, use the inverse of cos, to solve for [tex]\frac{x}{2}[/tex].
[tex]\frac{x}{2}[/tex] = [tex]cos^{-1}[/tex]( [tex]\frac{1}{2}[/tex])
[tex]\frac{x}{2}[/tex] = 60
Now you want to find x, so multiply both sides by 2.
x = 60 * 2 = 120
x can have many solutions; however, I have only given you one.