Question 212385
Let's say that 'x' can be negative. So let's plug in {{{x=-2}}}


The first equation is simply {{{y=-2}}} (after plugging in {{{x=-2}}}) which is a real number; however, the second equation {{{y=(sqrt(-2))^2}}} does not produce a real number. So the two are not equal when {{{x=-2}}}. They are not equal when {{{x<0}}}.



If we said that {{{x>=0}}}, then {{{x=(sqrt(x))^2}}} would be true.