Question

please help fast . Prove that ​

Answer 1

Answer:

hence proved

Step-by-step explanation:

let theta be a

=tan(45-a)=tan 45 +tan a /1-tan 45-tan a

=1+tan a /1-tan a

=1+ sin a/cos a / 1-sin a / cos a

=cos 2 a- sin 2 a

rationalising

cos 2 a-sin 2 a /(cos a-sin a) 2

cos 2 a /1-sin 2 a