Apply the trigonometric identity: $\tan\left(\theta \right)^m\cos\left(\theta \right)^n$$=\frac{\sin\left(\theta \right)^m}{\cos\left(\theta \right)^{\left(m-n\right)}}$, where $m=6$ and $n=2$

Multiplying the fraction by $\sin\left(x\right)$

Divide fractions $\frac{\frac{\sin\left(x\right)^{7}}{\cos\left(x\right)^{4}}}{\sqrt{x}}$ with Keep, Change, Flip: $\frac{a}{b}\div c=\frac{a}{b}\div\frac{c}{1}=\frac{a}{b}\times\frac{1}{c}=\frac{a}{b\cdot c}$