jika(1+tanA)(1+tanB) =2,maka nilai tan (A+B)=..

(1+tanA)(1+tanB)=2
1+tanA+tanB+tanAtanB=2
tanA+tanB+tanAtanB=1
tanA+tanB= 1-tanAtanB
maka tan(A+B)
tan(A+B)= tanA+tanB/1-tanAtanB
= 1-tanAtanB/1-tanAtanB
= 1
jadi tan(A+B)=1