Pochodna funkcji cosx

$f\left(x\right) =$	$\cos\left(x\right)$
$\dfrac{\mathrm{d}\left(f\left(x\right)\right)}{\mathrm{d}x} =$	$\class{steps-node}{\cssId{steps-node-1}{\tfrac{\mathrm{d}}{\mathrm{d}x}\kern-.25em\left(\cos\left(x\right)\right)}}$ $=\class{steps-node}{\cssId{steps-node-2}{-\sin\left(x\right)}}$

$f\left(x\right) =$

$\cos\left(x\right)$

$\dfrac{\mathrm{d}\left(f\left(x\right)\right)}{\mathrm{d}x} =$

$\class{steps-node}{\cssId{steps-node-1}{\tfrac{\mathrm{d}}{\mathrm{d}x}\kern-.25em\left(\cos\left(x\right)\right)}}$

$=\class{steps-node}{\cssId{steps-node-2}{-\sin\left(x\right)}}$