Question

1 + tan ^2 A / 1 + cot2 A= (1 -tan A/1- cot A) ^2 = tan 2 A( I am marking brainliest and giving 42 points! So do it!)

Answer 1

Given that: 1+tan² A1+cot²A=[1-tanA1-cotA]²=tan²A

We will first solve the equation on LHS

LHS:

= 1+tan²A / 1+cot²A

Using the trignometric identities we know that 1+tan²A= Sec²A and 1+cot²A= Cosec²A

= Sec²A/ Cosec²A

On taking the reciprocals we get

= Sin²A/Cos²A

= tan²A

RHS:

=(1-tanA)²/(1-cotA)²

Substituting the reciprocal value of tan A and cot A we get,

=(1-sinA/cosA)²/(1-cosA/sinA)²

=[(cosA-sinA)/cosA]²/ [(sinA-cos)/sinA)²

=(cosA-sinA)²×sin²A /Cos²A. /(sinA-cosA)²

=1×sin²A/Cos²A×1.

=tan

The values of LHS and RHS are same.

Hence proved