Question

solve: x^2-2x+4=0

Answer 1

quadratic formula
In: \[ax^2 + bx + c = 0\]
\[x _{1,2} = (-b \pm \sqrt{b^2-4ac}) / 2a\]
plug it in
\[x _{1,2} = (-(-2) \pm \sqrt{(-2)^2-4(1)(4)}) / 2(1)\]
which equals 2 plus or minus sqrt(4-16) = 2+2(i)sqrt(3) or 2-2(i)sqrt(3)
\[i = \sqrt{-1}\]