Question

prove that cos 55 degree. sin 35 degree+ sin55 degree cos 35 degree=1

Answer 1

LHS
=cos 55°.sin 35°+sin 55°.cos 35°
=cos (90°-35°).sin 35°+sin (90°-35°) cos35°
=sin 35°sin 35°+ cos 35°. cos 35°
=sin^2 35°+cos^2 35°
=1

LHS=RHS