Question

$Provethat:\frac{\cos {17}^{\circ }+\sin {17}^{\circ }}{\cos {17}^{\circ }-\sin {17}^{\circ }}=\tan {62}^{\circ }$

Answer 1

$\frac{\cos {17}^{\circ }+\sin {17}^{\circ }}{\cos {17}^{\circ }-\sin {17}^{\circ }}$

divide both numerator and denominator by

$\begin{array}{c}\cos {17}^{\circ }\\ \frac{1+\tan 17}{1-\tan 17}=\tan (45+17)=\tan {62}^{\circ }\end{array}$