Answer:
tan (7pi/8) = -4.4142
Step-by-step explanation:
The tangent half-angle formula is shown in the attached image
We have:
alpha = 7pi / 8
alpha/2 = 7pi / 16
Substitute in the formula with the alpha and alpha/2 as follows:
tan (7pi/8) = [2tan(7pi / 16)] / [1 - tan(7pi / 16)tan(7pi / 16)]
tan (7pi/8) = -4.4142
Hope this helps :)