Question

19. If A + B = 45°, prove that (1 + tan A)(1+tan B) = 2​

Answer 1

Step-by-step explanation:

1+tanB+tanA+tanA.tanB

tanA. tanB=tanA+tanB=1

do answer is 2

Answer 2

A+B=45°

tan(A+B)=tan45°

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

tan A+ tan B=1-tan A+ tan B

$\boxed{\huge{\bf{ADD\:\:1\:\: BOTH \:\: SIDE}}}$

tan A + tan B + tan A + tan B +1=1+1

tan A(1+tan B)+1(1+ tan B)=2

$\boxed{\huge{\bf{(1+tan B) (tan A+1}}}$