Circular Trigonometry Question

Question

Simplify by using the appropriate addition or subtraction formula.

tan 25° - tan 20°/1+tan 25° tan 20°

Which answer is it

A: no solution

B: tan 5°

C: tan 45°

Answer 1

This would equal tan 5.

By the angle subtraction identity for tan.

25 -20 = 5 and by the identity A = 25 and B = 20

tan (A - B) = tan A - tan B/ ( 1 + tan A tan B)