How do you find the roots, real and imaginary, of y= (x-3)^2+(x-4)^2 using the quadratic formula?

1 Answer
Apr 24, 2016

x = 7/2+-1/2i

Explanation:

First multiply out the quadratic to get it into standard form:

y = (x-3)^2+(x-4)^2

=x^2-6x+9+x^2-8x+16

=2x^2-14x+25

This is now in the form ax^2+bx+c with a=2, b=-14 and c=25

This has zeros given by the quadratic formula:

x = (-b+-sqrt(b^2-4ac))/(2a)

=(14+-sqrt((-14)^2-4(2)(25)))/(2*2)

=(14+-sqrt(196-200))/4

=(14+-sqrt(-4))/4

=(14+-sqrt(4)i)/4

=7/2+-1/2i