Question

Find the value of Sgn(-1) + sgn(0) + Sgn(1), where Sgn(x) is the signum function.

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Answer 1

$Sgn\left(x\right)=\{\begin{array}{cc}1,& ifxgt0\\ 0,& ifx=0\\ -1& ifx<0\end{array}$
So we can say it basically gives the sign of the input.
Sgn(-1) = -1
Sgn(0) = 0
Sgn(1) = 1
$\Rightarrow$ Sgn(-1) + Sgn(1) = 0