1=-3*-cos(-3x)

Solution for 1=-3*-cos(-3x) equation:

Simplifying
1 = -3 * -1cos(-3x)

Remove parenthesis around (-3x)
1 = -3 * -1cos * -3x

Reorder the terms for easier multiplication:
1 = -3 * -1 * -3cos * x

Multiply -3 * -1
1 = 3 * -3cos * x

Multiply 3 * -3
1 = -9cos * x

Multiply cos * x
1 = -9cosx

Solving
1 = -9cosx

Solving for variable 'c'.

Move all terms containing c to the left, all other terms to the right.

Add '9cosx' to each side of the equation.
1 + 9cosx = -9cosx + 9cosx

Combine like terms: -9cosx + 9cosx = 0
1 + 9cosx = 0

Add '-1' to each side of the equation.
1 + -1 + 9cosx = 0 + -1

Combine like terms: 1 + -1 = 0
0 + 9cosx = 0 + -1
9cosx = 0 + -1

Combine like terms: 0 + -1 = -1
9cosx = -1

Divide each side by '9osx'.
c = -0.1111111111o-1s-1x-1

Simplifying
c = -0.1111111111o-1s-1x-1