2017­3­30 complete square day 1.notebook
Today is Thursday
3/30/17
Do Now:
-Take calculator
-Copy HW
-Text section 9.4
pg. 511 #5-23 odd
-Chapter 9 test Thursday 4/6
Today's Objective:
Complete the Square Day 1
March 30, 2017
2017­3­30 complete square day 1.notebook
March 30, 2017
Multiply the following polynomials
(x + 5)
(x - 3)
2
2
Write each of the following in factored form
2
2
x + 20x + 100
x - 8x + 16
All of the above are perfect square trinomials. Do you notice a
relationship between the values of b and c when it is in standard
form?
Find the value of c that will make the trinomial a perfect square trinomial. (hint, take half of b and square it)
2
x + 6x + c
x2 ­10x + c x2 − 9x + c
2017­3­30 complete square day 1.notebook
March 30, 2017
Solving a quadratic by completing the square
2
x + 6x = 10
2
x + 6x +
(
= 10 +
Step 1: Make sure constant term is on opposite side.
Step 2: Complete the square to make a perfect square trinomial.
Step 3: Add the number to both sides of the equation.
2
) =
Step 4: Factor the perfect square trinomial.
Step 5: Solve using square roots.
*Your answer may have a radical sign. Make sure you simplify*
2017­3­30 complete square day 1.notebook
Solve x2 − 16x = −15 by completing the square.
Can you think of a way to write the following in factored form?
y = x2 ­ 8x ­ 4
Solve the quadratic by completing the square
March 30, 2017
2017­3­30 complete square day 1.notebook
March 30, 2017
Solve the quadratics
x2 − 2x = 3 m2 + 12m = −8
Summary:
Completing the square is another way we
can solve quadratic equations.
This process is useful when we cannot
write the quadratic in factored form.
This process works every time.
2017­3­30 complete square day 1.notebook
March 30, 2017