Question

Question #d3719

Answer 1

`x=cos^-1(sqrt(3/5))`
`x=cos^-1(-sqrt(3/5))`

Explanation:

`5cos^2(x)-3=0`

Add 3

`5cos^2(x)=3`

Divide by 5

`cos^2(x)=3/5`

Square root

`cos(x)=+-sqrt(3/5)`