Question 1130401
.
<pre>
{{{cos(2x) + sin(2x))^2}}} = {{{cos^2(2x) + 2*cos(2x)*sin(2x) + sin^2(2x)}}} = {{{(cos^2(2x) + sin^2(2x))}}} + {{{2*cos(2x)*sin(2x)}}} = 1 + 4*sin(2x).
</pre>

Completed, proved and solved.