Adv. Alg 2 2.4 Completing the square
Objective: Solve Quadratic equations by completing the square; Write quadratic equations in vertex form
: Solve each equation
3x2 - 4 = 68
(x – 7)2 = 16
Solving equations by completing the square
2x2 -5x - 4 = 0
3k2 + 42x
=
-24
Vertex form of a quadratic equation

We will convert a quadratic in standard form to vertex form in Algebra 2.

Note that in VERTEX form, the vertex of the parabola is
(h,k)
EX 1. f(x) = x2 – 4x + 5
We balance the
equation here
by adding and
subtracting on
the SAME side
(put in vertex form; identify vertex)
f(x) = x2 - 4x + ___________ + 5 - _______
Complete the square!!
You try: Convert a quadratic in standard form into vertex form by completing the square
f(x) = x2 -4x + 13
HW : pgs 89-90 20,22,26,28,33,37,50,64*
h(x) = 9x2 + 18x – 3