Pochodna funkcji cosax

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

$f\left(x\right) =$

$\cos\left(a\right){\cdot}x$

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

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

$=\class{steps-node}{\cssId{steps-node-2}{\cos\left(a\right)}}$