Question #01ea9

1 Answer
Dec 4, 2016

tan (pi/8) = 1/(1+sqrt(2))

Explanation:

We have that:

tan (pi/8) = tan(1/2*pi/4)

Using the half angle formulae:

tan (alpha/2) = frac sin alpha (1+cos alpha)

tan (pi/8) = frac sin(pi/4) (1+cos(pi/4)) = frac (sqrt(2)/2) (1+sqrt(2)/2) = 1/(1+sqrt(2))