How do you write in vertex form for y=x^2 + .6x - 11 by completing the square?

1 Answer
Alan P.
Jun 2, 2015

The general squared binomial is (x+a)^2 = x^2+2ax+a^2

Given the equation y= x^2+.6x-11

If the coefficient of x is (0.6)
then
in terms of the general form a=0.3 and a^2 = 0.09

Writing as a completed square:
color(white)("XXXXX")y = (x+0.3)^2 -11 -0.09

color(white)("XXXXX")y = (x - (-0.3))^2 + (-11.09)

which is the vertex form
color(white)("XXXXX")with the vertex at (-0.3,-11.09)

Related questions
See all questions in Completing the Square
Impact of this question
1931 views around the world
You can reuse this answer
Creative Commons License