Question

ten 50°-ten 40°=2ten 10°​

Answer 1

Answer:

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

A=50       B=40 deg.

Tan 50 = cot (90-50)=1/tan40.

LHS = tan(50-40) x (1+ tan50 x tan40)

= tan10 x (1+1)

= 2 tan 10

Hence, LHS = RHS