cos^2(s)(1-tan(s))(1+tan(s))=cos(20)

Solution for cos^2(s)(1-tan(s))(1+tan(s))=cos(20) equation:

Simplifying
cos2(s)(1 + -1tan(s))(1 + tan(s)) = cos(20)

Multiply ant * s
cos2 * s(1 + -1anst)(1 + tan(s)) = cos(20)

Multiply ant * s
cos2 * s(1 + -1anst)(1 + anst) = cos(20)

Multiply cos2 * s
cos3(1 + -1anst)(1 + anst) = cos(20)

Multiply (1 + -1anst) * (1 + anst)
cos3(1(1 + anst) + -1anst * (1 + anst)) = cos(20)
cos3((1 * 1 + anst * 1) + -1anst * (1 + anst)) = cos(20)
cos3((1 + 1anst) + -1anst * (1 + anst)) = cos(20)
cos3(1 + 1anst + (1 * -1anst + anst * -1anst)) = cos(20)
cos3(1 + 1anst + (-1anst + -1a2n2s2t2)) = cos(20)

Combine like terms: 1anst + -1anst = 0
cos3(1 + 0 + -1a2n2s2t2) = cos(20)
cos3(1 + -1a2n2s2t2) = cos(20)
(1 * cos3 + -1a2n2s2t2 * cos3) = cos(20)

Reorder the terms:
(-1a2cn2os5t2 + 1cos3) = cos(20)
(-1a2cn2os5t2 + 1cos3) = cos(20)

Reorder the terms for easier multiplication:
-1a2cn2os5t2 + 1cos3 = 20cos

Solving
-1a2cn2os5t2 + 1cos3 = 20cos

Solving for variable 'a'.

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

Add '-1cos3' to each side of the equation.
-1a2cn2os5t2 + 1cos3 + -1cos3 = 20cos + -1cos3

Combine like terms: 1cos3 + -1cos3 = 0
-1a2cn2os5t2 + 0 = 20cos + -1cos3
-1a2cn2os5t2 = 20cos + -1cos3

Divide each side by '-1cn2os5t2'.
a2 = -20n-2s-4t-2 + n-2s-2t-2

Simplifying
a2 = -20n-2s-4t-2 + n-2s-2t-2

Reorder the terms:
a2 + 20n-2s-4t-2 + -1n-2s-2t-2 = -20n-2s-4t-2 + 20n-2s-4t-2 + n-2s-2t-2 + -1n-2s-2t-2

Combine like terms: -20n-2s-4t-2 + 20n-2s-4t-2 = 0
a2 + 20n-2s-4t-2 + -1n-2s-2t-2 = 0 + n-2s-2t-2 + -1n-2s-2t-2
a2 + 20n-2s-4t-2 + -1n-2s-2t-2 = n-2s-2t-2 + -1n-2s-2t-2

Combine like terms: n-2s-2t-2 + -1n-2s-2t-2 = 0
a2 + 20n-2s-4t-2 + -1n-2s-2t-2 = 0

The solution to this equation could not be determined.