Question

tan69+tan66÷1-tan69tan66=-1

Answer 1

We have to use
formula
Tan(A+B) = TanA+TanB/(1-TanATanB)

tan69+tan66+1=tan69tan66
Here A= 69 and B= 66

Tan(69+66)=
Tan69+Tan66/(1-Tan69Tan66)

Tan 135 = Tan69+Tan66/(1-Tan69Tan66)

we know Tan135= -1

-1 =Tan69+Tan66/(1-Tan69Tan66)

Tan69Tan66 -1 = Tan69+Tan66

Tan69Tan66 = 1+ Tan66 +Tan69

@skb

Answer 2

Answer:

HERE IS YOUR PROFF:-

Step-by-step explanation:

tan(69)+tan(66)/1-tan(69)tan(66)=

tan(69+66)=

tan(135)=

tan(90+45)=

-cot(45)=

-1