Question

If Lylah completes the square for f(x) = x^2 - 12x + 7 to find the minimum, she must write f(x) in the general form f(x) = (x - a)^2 + b. What is the value a for f(x)?

Answer 1

@Directrix

Answer 2

I think that Lylah is writing the equation of the parabola in vertex form. See attachment.

Answer 3

The first step is to complete the square for this:

f(x) = x^2 - 12x + 7

Answer 4

x^2 - 12x + ___ = - 7 + ____

To find the expression that goes in the blank to form a square, do this:

Take half of the coefficient (don't forget the sign) of the x-term, and square it. Add this square to both sides of the equation.