Quadratic formula and discriminant

Quadratic formula and discriminant

Multiple Choice

Solutions of a quadratic equation are also called

• roots

• x-intercepts

• zeros

• All of the above

Multiple Choice

What method would you use to solve $x^2-16=0$   

• Factoring Method

• Completing the Square Method

• Quadratic Formula

• Square Root Method

Multiple Choice

Identify a, b and c in the quadratic equation: $2x^2-3x-5=0$   

• a = 2 , b = 3, c = -5

• a = 2, b = -3, c = 5

• a = 2, b = -3, c = -5

• a = -2, b = 3, c = 5

Multiple Choice

What is the quadratic formula?

• $x=\frac{b-\sqrt{\left(b\right)^2-4\left(a\right)\left(c\right)}}{2\left(a\right)}$

• $x=\frac{-\left(b\right)\pm\sqrt{\left(b\right)^2-4\left(a\right)\left(c\right)}}{2\left(a\right)}$

• $x=\frac{\left(b\right)\pm\sqrt{\left(b\right)^2-4\left(a\right)\left(c\right)}}{2a}$

• $x=-\left(b\right)\pm\sqrt{b\pm4\left(a\right)\left(c\right)}$

The Discriminant will tell you the number of solutions you have.

Discriminant = b² - 4ac

If the discriminant is:

• positive , then you have 2 real solutions

• negative, then you have 2 imaginary solutions (no real)

• zero - then you have one solution (double root)

Multiple Choice

What does the discriminant tell us about a quadratic function?

• The maximum or minimum value

• The y-intercept

• The number and type of solutions

• The axis of symmetry

Multiple Choice

What is the formula for the discriminant of a quadrartic equation?

•  $\frac{-b}{2a}$  

•  $b^2-4ac$  

•  $ax^2+bx+c$  

•  $\frac{-b\pm\sqrt{b^2-4ac}}{2a}$  

Multiple Choice

If the discriminant is equal to -2, how many real solutions are there?

• None

• One

• Two

• Infinite

Multiple Choice

If the discriminant of the quadratic equation is equal to 4, how many real solutions are there?

• None

• One

• Two

• Infinite

Multiple Choice

If the discriminant of the quadratic equation is equal to 0, how many real solutions are there?

• None

• One

• Two

• Infinite

Multiple Choice

Which is the correct set-up of the discriminant for:
 $3x^2-19x=-20$  

•  $\left(-19\right)^2-4\left(3\right)\left(20\right)$  

•  $\left(-19\right)^2-4\left(3\right)\left(-20\right)$  

•  $\left(-20\right)^2-4\left(3\right)\left(-19\right)$  

•  $-\left(-19\right)^2-4\left(3\right)\left(-20\right)$  

Multiple Choice

What is the discriminant of this equation?

3x² + 8x = 0

• 64

• 52

• 9

• 0

Multiple Choice

For the function below, determine if the discriminant is positive, negative, or zero?

___________

y = x² + 4x + 4

• Positive

• Negative

• Zero

Multiple Choice

What is the value of the discriminant of 6x² − 2x − 3 = 0

• 76

• 29

• 68

• none of these

Multiple Choice

What is the value of the discriminant of -2x² − x − 1 = 0

• 76

• -7

• 9

• none of these

Multiple Choice

____________

For the function above, determine whether the discriminant is positive, negative, or zero.

• Positive

• Negative

• Zero