Question

Prove the above question​

Answer 1

Answer:

cos 20 + sin 20 / cos 20 - sin 20

= cos 20( 1+ sin 20/ cos 20)/cos 20(1- sin 20/ cos 20)

= cos 20+ sin 20/ cos 20 - sin 20

= cos 20(1+ sin 20/ cos 20)/ cos 20(1-sin 20/ cos 20)

= cos 20 ( 1+ tan 20)/ cos 20(1- sin 20

= 1+ tan 20/1- tan20

= 1+ tan 20/1- tan20= tan (45-20)

=tan 45

HENCE PROVED