Today, we will start with perfect square trinomials and The quadratic Formula
First : Perfect Square Trinomials
I will help you know more about that with first example :
We have already discussed perfect square trinomials:
We know : : Square of first term of binomial
2ab : twice the product of binomial’s first and last terms
: Square of last term of binomial
Let’s start with example :
Factor :
Like my way, i always try the last term the numbers multiply together to get it like this :
36×1
18×2
12×3
9×4
6×6
I will choose 6×6 because if they multiply together, i will get 36 and when they add together, i will get 12 like the exercise i gave above.
You can do it faster than my way with perfect square.
Answer: (x+6)(x+6) or
Example 2 :
The leading coefficient is not 1 (). Its 9 but Both and 1 are perfect squares, and 6x is twice the product of 3x and 1.
So we will know a = 3a and b = 1.
Then get the answer : or (3x-1)(3x-1)
Quadratic Formula : We will use this formula when we can not use Factoring and Binomial with complicated exercise. This formula will help us get answer easier and faster.
And now let’s start :
We knew : a=2
b=6
c=9
We will apply this formula :