# Thread: simplifying trignometric identity

1. ## simplifying trignometric identity

how would you simplify 2sin3xcosx=1
i've been stuck on this question for some time ;[

2. consider $sin(a)cos(b) = \frac{1}{2}[sin(a+b)+sin(a-b)]
$

$2sin(3x)cos(x)=1$

$2(\frac{1}{2}[sin(3x+x)+sin(3x-x)])=1$

$sin(3x+x)+sin(3x-x)=1$

$
sin(4x)+sin(2x)=1
$