code class$=$"asciimath"$>$A spinless electron is in the ground state of a potential V$($x$)=-\backslash$alpha $\backslash$delta $($x$)$ with $\backslash$alpha $>0.$ To first non$-$trivial order, what is the change in the ground state due to a weak electric field E$>0.$ Approximately, up to what value of E$,$ is your calculation valid?