0.86=exp(-2*pi*f)

Solution for 0.86=exp(-2*pi*f) equation:

Simplifying
0.86 = exp(-2pi * f)

Multiply ip * f
0.86 = epx(-2fip)

Remove parenthesis around (-2fip)
0.86 = epx * -2fip

Reorder the terms for easier multiplication:
0.86 = -2epx * fip

Multiply epx * fip
0.86 = -2efip2x

Solving
0.86 = -2efip2x

Solving for variable 'e'.

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

Add '2efip2x' to each side of the equation.
0.86 + 2efip2x = -2efip2x + 2efip2x

Combine like terms: -2efip2x + 2efip2x = 0
0.86 + 2efip2x = 0

Add '-0.86' to each side of the equation.
0.86 + -0.86 + 2efip2x = 0 + -0.86

Combine like terms: 0.86 + -0.86 = 0.00
0.00 + 2efip2x = 0 + -0.86
2efip2x = 0 + -0.86

Combine like terms: 0 + -0.86 = -0.86
2efip2x = -0.86

Divide each side by '2fip2x'.
e = -0.43f-1i-1p-2x-1

Simplifying
e = -0.43f-1i-1p-2x-1