# How do I find the derivative of f(x)=2sin(x)cos(x)?

You can use the Product Rule where the derivative of $f \left(h\right) \cdot g \left(x\right)$ is equal to: $f ' \left(x\right) \cdot g \left(x\right) + f \left(x\right) \cdot g ' \left(x\right)$
$2 \cos \left(x\right) \cos \left(x\right) + 2 \sin \left(x\right) \left(- \sin \left(x\right)\right) =$
$= 2 \left({\cos}^{2} \left(x\right) - {\sin}^{2} \left(x\right)\right)$