# Simplify $-2\sin(x)\cos(x)-2\cos(x)$

Simplify $-2\sin(x)\cos(x)-2\cos(x)$

The above expression is the derivative of a function, and part of a larger problem. I am wanting to simplify this to the form $-2(\sin(x)+1)\cos(x)$. I'm having trouble figuring out how to simplify this, even though I know where I am supposed to end up. Any help or hints would be appreciated.

• Factor out $-2\cos(x)$ and you get the desired result. – Christian Ivicevic Nov 7 '15 at 18:37
• If it is for a derivative of a function ,I prefer to rewrite it as $−2sin(x)cos(x)−2cos(x) =\\-sin(2x)-2cos(x)$ – Khosrotash Nov 7 '15 at 18:38
• That's what I was looking for. Thanks to you both! – McB Nov 7 '15 at 18:39
• There's something fishy here. Somebody is learning calculus, but they can't simplify $-2\sin(x)\cos(x)-2\cos(x)$ to $-2(\sin(x)+1)\cos(x)$? It doesn't make sense. – TonyK Nov 7 '15 at 18:43
• It was simply dumb oversight on my part... Sorry! @TonyK – McB Nov 7 '15 at 18:44

Hint: You have a common factor of $-2\cos(x)$ in both terms.