# solve -3cos(-3x+a)=0

### 1 Answer | Add Yours

-3cos(-3x+a) = 0

Divide by -3 => cos(-3x+a) = 0

The cosine function is cancelling out if `-3x+a = +-pi/2`

Solve `-3x+a = +pi/2gt -3x =pi/2 - a =gt x = -pi/6 + a/3`

Solve `-3x+a = -pi/2gt -3x =-pi/2 - a =gt x = pi/6 + a/3`

**The solutions of equation depend on the parameter a: `x =a/3 - pi/6; x = pi/6 + a/3` **