How do you factor x^2-2x+2x2−2x+2 ?
Responda:
This quadratic only factors with the help of Complex coefficients:
x^2-2x+2 = (x-1-i)(x-1+i)x2−2x+2=(x−1−i)(x−1+i)
Explicação:
Dado:
x^2-2x+2x2−2x+2
Isto está na forma ax^2+bx+cax2+bx+c com a=1a=1, b=-2b=−2 e c=2c=2
It has discriminant Delta given by the formula:
Delta = b^2-4ac = (color(blue)(-2))^2-4(color(blue)(1))(color(blue)(2)) = 4 - 8 = -4
Desde Delta < 0, this quadratic has no Real zeros and no linear factors with Real coefficients.
We can still factor it, but we need to use Complex coefficients.
A diferença da identidade dos quadrados pode ser escrita:
A^2-B^2 = (A-B)(A+B)
To factor our quadratic, we can complete the square and use the difference of squares identity with A=(x-1) e B=i como se segue:
x^2-2x+2 = x^2-2x+1+1
color(white)(x^2-2x+2) = (x-1)^2+1
color(white)(x^2-2x+2) = (x-1)^2-i^2
color(white)(x^2-2x+2) = ((x-1)-i)((x-1)+i)
color(white)(x^2-2x+2) = (x-1-i)(x-1+i)