Question

prove that



( cos 17 +sin 17 )/(cos 17-sin17) = tan 62

Answer 1

Let x = ( cos17 + sin17 ) / ( cos17 − sin17 )

  Dividing Numerator & Denominator by cos 17

         = ( 1 + tan17 ) / ( 1 − tan17 )

We know tan 45 = 1,
         = ( tan45 + tan17 ) / ( 1 − tan45.tan17 )

tan( A + B ) = tan A + tan B /  1 - tan A.tan B  
         
         = tan62

Thus, ( cos 17 +sin 17 )/(cos 17-sin17) = tan 62