How do you solve x^2-2x+2 by completing the square?

1 Answer
Jun 12, 2015

x=1+i

x=1-i

Explanation:

Make a perfect square trinomial by completing the square. A perfect square trinomial has the form of a^2+2ab+b^2=(a+b)^2 or a^2-2ab+b^2=(a-b)^2.

x^2-2x+2=0

Subtract 2 from both sides of the equation.

x^2-2x=-2

Divide the coefficient of the x term by 2 and square the result. Add it to both sides of the equation.

(-2)/2=-1; -1^2=1

x^2-2x+1=-2+1 =

x^2-2x+1=-1

There is now a perfect square trinomial on the left side of the equation.

Factor the trinomial.

(x-1)^2=-1

Take the square root of both sides and solve for x.

x-1=+-sqrt(-1)

x-1=+-i

x=1+-i