Question Number 204688 by Davidtim last updated on 25/Feb/24
![f(x)=sgn(x); f^′ (x)=(d/dx)[f(x)]=?](Q204688.png)
$${f}\left({x}\right)={sgn}\left({x}\right);\:\:\:\:\:{f}^{'} \left({x}\right)=\frac{{d}}{{dx}}\left[{f}\left({x}\right)\right]=? \\ $$
Answered by Faetmaaa last updated on 27/Feb/24
![(d/dx)[f∣_(]−∞, 0[) (x)] = (d/dx)[f∣_(]0, +∞[) (x)] = 0](Q204803.png)
$$\frac{\mathrm{d}}{\mathrm{d}{x}}\left[{f}\mid_{\left.\right]−\infty,\:\mathrm{0}\left[\right.} \left({x}\right)\right]\:=\:\frac{\mathrm{d}}{\mathrm{d}{x}}\left[{f}\mid_{\left.\right]\mathrm{0},\:+\infty\left[\right.} \left({x}\right)\right]\:=\:\mathrm{0} \\ $$