Question 169395
<pre><font size = 4 color = "indigo"><b>

{{{sin(A)cos(2A)+ cos(A)sin(2A)}}}

Use the identity 

{{{sin(alpha+beta)=sin(alpha)cos(beta)+cos(alpha)sin(beta)}}}

with {{{alpha=A}}} and {{{beta=2A}}}

{{{sin(A+2A)=sin(A)cos(2A)+cos(A)sin(2A)}}}

The right side is what you are asking, so the
answer is the left side {{{sin(A+2A)}}}, or

{{{sin(3A)}}}

Edwin</pre>