Question

If A+B = 225°,Then what will the value of 1+cotA/cotA .1+cotB/cotB​

Answer 1

Answer:

Changing cot in terms of tan we have to prove that

1/1+tanA . 1/1+tanB = 1/2

or 2=1+tanA+tanB+tanAtanB

or tanA+tanB=(1−tanAtanB)

or

1−tanAtanB

tanA+tanB

=1 or tan(A+B)=1

or tan225 =1

But tan225 = tan(180- + 45 ) = tan45 = 1