Question 1119007
<pre>
{{{matrix(1,3,


(1^""^"" + cos(A^""))^2/(sin^2(A)^""),""="", (1 + cos(A^"")^""^"")/(1 - cos(A^"")^""))}}}

Multiply the right side by the conjugate of the bottom
over itself, which just equal 1. That is, we multiply the
roght side by {{{(1 + cos(A^"")^""^"")/(1 + cos(A^"")^"")}}}

{{{matrix(1,17,"","","","","","","","","","","","",
"",""="", expr((1 + cos(A^"")^""^"")/(1 - cos(A^"")^"")),"×",(1 + cos(A^"")^""^"")/(1 + cos(A^"")^""))}}}

{{{matrix(1,15,"","","","","","","","","","","","",
"",""="", (1^""^"" + cos(A^""))^2/(1-cos^2(A)^""))}}}

{{{matrix(1,15,"","","","","","","","","","","","",
"",""="", (1^""^"" + cos(A^""))^2/(cos^2(A)^""))}}}

Edwin</pre>