Anatomy of a Quadratic Function. Quadratic Form Any function that can be written in the form Ax 2...

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Anatomy of a Quadratic Function

Transcript of Anatomy of a Quadratic Function. Quadratic Form Any function that can be written in the form Ax 2...

Anatomy of a Quadratic Function

Quadratic Form

Any function that can be written in the form Ax2+Bx+C where a is not equal to zero.

You have already been looking at quadratics

Anything with an x2 term in the equation

Creating a quadratic

Done by foiling Example (3x+2)(2x-4)

To be a quadratic…

Must have an x2 term Must have a constant number not

equal to zero. Proper form: Ax2+ Bx +C Practice identifying

Create the quadratic…

Foil to get the quadratic, and label a, b, and c

(2x-1)(3x+5)

Foil to get the quadratic, and label a, b, and c

(2x-5)(x-2)

Quadratic Function

How do I know it’s a function?

The parabola Graph of a quadratic function is a parabola It’s the “U” shape Upward opening parabola- the coefficient

with the x2 term is positive

Downward opening parabola- The coefficient with the x2 term is negative

Axis of Symmetry

Each parabola has an axis of symmetry

Axis of symmetry- line that divides a parabola into two parts that are mirror images of one another

DO IT

The parabola

Vertex- lowest point or highest point on a graph

Max and Min Values

If the parabola opens up, the min value is at the vertex

If the parabola opens down, the max value is at the vertex

The axis of symmetry passes through the vertex of the parabola

Domain and Range

Domain of a parabola is all real numbers

Range of a parabola

Depends on where the parabola sits…

Solving Quadratic Functions

Square Roots

x2=a where a is any number greater than or equal to 0

x is called the square root of a The solution, x has two values

aa ,

Properties of Square Roots

Positive square root is called the principal root

Properties of square roots

b

a

b

aba

baabba

,0,0

*,0,0

Solve

Solve just like a regular equation Follow order of operations, but leave

square root till the end Simplify all other ways first

4x2 +13=253

5x2-19=231

9(x-2)2=121

4(x+2)2=49

Warm Up!

Complete this problem at the bottom of your sheet

Solve 4x2+5=20

Solving using the Calculator

Quadratic formulas can have more than one solution

Because a square root of a number can give a positive and negative number

They can also have no solutions, or just one

So how do I know if I am right?

Use your calculator Solve so the entire equation is set

equal to 0 Go to y= on your calculator Plug the equation into y1 Look for the x intercepts of the graph Use the Solve key to find values

Pythagorean Theorem

a2 + b2 =c2

Works only for right triangles What is a right triangle?

Homework: page286

#15, 18, 21, 24, 27, 30