# Question #d2f6c

If ${\sin}^{4} A + {\sin}^{2} A = 1$ then ${\sin}^{4} A = {\cos}^{2} A$ and also
${\tan}^{2} A = \frac{1}{\sin} ^ 2 A$ or dividing $\frac{1}{\tan} ^ 2 A = {\sin}^{2} A$ and this conclusion solves the problem.