Could someone explain the steps for this question.

Question

Simplify the expression

tan(5pi/8)-tan(3pi/8)/1+tan(5pi/8)tan(3pi/8)

Answer 1

Options are

a) 0
b) 1
c) -1
d) undefined

Answer 2

Recall your sum/difference formulas. You have

tan(5pi/8-3pi/8) = tan(pi/4)
so, (B)