Question 602435
<pre>

The trick is that if you see any of these:

{{{1 + cos(theta)}}}, {{{1 - cos(theta)}}}, {{{1 + sin(theta)}}}, {{{1 - sin(theta)}}}, you can change them to either {{{1 - cos^2(theta)}}} or {{{1 - sin^2(theta)}}},
which are identities for {{{sin^2(theta)}}} or {{{cos^2(theta)}}} respectively, by multiplying and
dividing by the conjugate.  There is one of these on the bottom of the right
side, so start with the right side and do just that:

{{{(1-3cos(theta)-4cos^2(theta))/sin^2(theta))}}} = {{{(1-4cos(theta))/(1-cos(theta))}}}

               = {{{expr((1-4cos(theta))/(1-cos(theta)))*expr((1+cos(theta))/(1+cos(theta)))}}}

               = {{{(1+cos(theta)-4cos(theta)-4cos^2(theta))/(1+cos(theta)-cos(theta)-cos^2(theta))}}}

               = {{{(1-3cos(theta)-4cos^2(theta))/(1-cos^2(theta))}}}

               = {{{(1-3cos(theta)-4cos^2(theta))/sin^2(theta)}}}
Edwin</pre>