Answer:
Step-by-step explanation:
[tex]\text{The quadratic equation:}\ ax^2+bx+c=0.\\\\\text{We have}\ x^2-4x+2=0\\\\a=1,\ b=-4,\ c=2\\\\\text{Substitute to}\ b^2-4ac:\\\\b^2-4ac=(-4)^2-4(1)(2)=16-8=8[/tex]