Apply the trigonometric identity: $\frac{1}{\csc\left(\theta \right)}$$=\sin\left(\theta \right)$

Applying the tangent identity: $\displaystyle\tan\left(\theta\right)=\frac{\sin\left(\theta\right)}{\cos\left(\theta\right)}$

Divide fractions $\frac{1}{\frac{\sin\left(x\right)}{\cos\left(x\right)}}$ with Keep, Change, Flip: $a\div \frac{b}{c}=\frac{a}{1}\div\frac{b}{c}=\frac{a}{1}\times\frac{c}{b}=\frac{a\cdot c}{b}$