Quadratic Equations

What is the degree of the polynomial below:

 $3x^3\ -\ 2x^2\ +\ 4x\ -\ 9$  ?

What is the degree of the polynomial below:

 $8\ +\ 4x^4\ -\ 7x^6$  ?

What do you call an equation whose degree is 2?

• cubic

• linear

• quadratic

• quartic

• quintic

Evaluate the quadratic equation below when x = 5.

 $y\ =\ x^2\ -\ x\ -\ 6$  

Evaluate the quadratic equation below when x = -1.

 $y\ =\ 2x^2\ \ -\ 9$  

Evaluate the quadratic equation below when x = -6.

 $y\ =\ -3x^2\ \ +\ 4x\ -\ 5$  

Is x = 5 a solution of the quadratic equation  $y\ =\ 2x^2\ -\ 9x\ -\ 5$ ? To answer this, evaluate the quadratic equation when x = 5. 

• True

• False

Is x = -6 a solution of the quadratic equation  $y\ =\ x^2\ +\ 13x\ +\ 42$ ? To answer this, evaluate the quadratic equation when x = -6.

• True

• False

Is x =  $\frac{1}{3}$  a solution of the quadratic equation  $y\ =\ 6x^2\ -\ 7x\ +\ 2$ ? To answer this, evaluate the quadratic equation when x =  $\frac{1}{3}$ . 

• True

• False

What do you call the u-shaped graph of a quadratic equation?