5cos^2x-7cosx-1=0

Solution for 5cos^2x-7cosx-1=0 equation:

Simplifying
5cos2x + -7cosx + -1 = 0

Reorder the terms:
-1 + -7cosx + 5cos2x = 0

Solving
-1 + -7cosx + 5cos2x = 0

Solving for variable 'c'.

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

Add '1' to each side of the equation.
-1 + -7cosx + 1 + 5cos2x = 0 + 1

Reorder the terms:
-1 + 1 + -7cosx + 5cos2x = 0 + 1

Combine like terms: -1 + 1 = 0
0 + -7cosx + 5cos2x = 0 + 1
-7cosx + 5cos2x = 0 + 1

Combine like terms: 0 + 1 = 1
-7cosx + 5cos2x = 1

Reorder the terms:
-1 + -7cosx + 5cos2x = 1 + -1

Combine like terms: 1 + -1 = 0
-1 + -7cosx + 5cos2x = 0

The solution to this equation could not be determined.