Question

Decide whether $y=2$ is a root of the quadratic equation:
$y^2-4y+2=0$

Answer 1

The given equation is
$y^2-4y+2=0$
Put $y=2$
$(2{)}^2-4(2)+2=0$
$4-8+2\ne 0$
$\therefore y=2$ is not a root of the given equation