I'm a bit rusty in mathematics so I need your help please :)
I need a function $y$ that satisfies: $\begin{align*} y &= ax\\ y &= \left\{\begin{array}{ll} x &\text{if }x\geq 0;\\ 0 &\text{if }x\lt 0. \end{array}\right. \end{align*}$
Is there a way to do this? What should $a$ be like? I believe I need something that is $1$ for positive value and $0$ for negative.
Thank you