+26367 how to solve this
\(\sin^4 ( A ) + \sin^2 ( A ) \cos^2 ( A ) + \cos^2 ( A ) = 1\)
\(\begin{array}{|rcll|} \hline \sin^4 ( A ) + \sin^2 ( A ) \cos^2 ( A ) + \cos^2 ( A ) &=& 1 \\ \sin^2 ( A )\sin^2 ( A )+ \sin^2 ( A ) \cos^2 ( A ) + \cos^2 ( A ) &=& 1 \\ \sin^2 ( A ) \left(\sin^2 ( A )+ \cos^2 ( A )\right) + \cos^2 ( A ) &=& 1 \\ \sin^2 ( A ) \left(\underbrace{\sin^2 ( A )+ \cos^2 ( A )}_{=1} \right) + \cos^2 ( A ) &=& 1 \\ \sin^2 ( A )*1 + \cos^2 ( A ) &=& 1 \\ \underbrace{\sin^2 ( A ) + \cos^2 ( A )}_{=1} &=& 1 \\ \hline \end{array} \)
