Question

if A=60 degree and B=30 degree, verify that tan (A-B)= tan A-tan B/1+tan A tan B

Answer 1

hello,
A=60° B=30°
LHS=tan(A-B)=tan(60°-30°)
=tan(30°) which is equal to 1/√3
now,
RHS=tanA-tanB/1+tanAtanB
=tan60°-tan30°/1+tan60°tan30°
tan60°=√3 tan30°=1/√3
=√3-1/√3/1+√3·1/√3
in numerator taking LCM
=(√3·√3-1)/√3/1+1              √3×1/√3=1
=(3-1)/√3/2        
=2/√3/2
2/√3×1/2
=1/√3
LHS=RHS 
hence verified
hope this helps