Discriminant

1 The discriminant is

• aX² + bX + c

• b - 4ac

• b² - 4ac

• b² + 4ac

1 In the equation

y = x² +5x +7,

match each leading coefficient with its correct letter.

• a=0, b=5, c=7

• a=1, b=5, c=7

• a=7, b=5, c=1

1 What does the discriminant tell us?

• The maximum or minimum

• The y-intercept

• The number and type of solutions

• The axis of symmetry

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

y = x² + 4x + 4

• Positive

• Negative

• Zero

2 A function has a discriminant of 4.

How many x-intercepts does it have?

• 0

• 1

• 2

• 4

2 A function has a discriminant of 0.

How many x-intercepts does it have?

• 0

• 1

• 2

• 5

3 What is the discriminant of

-2x² − x − 1 = 0 ?

• 76

• -7

• 9

• none of these

3 For the function above, is the discriminant positive, negative, or zero?

• Positive

• Negative

• Zero

3 For the function above, is the discriminant positive, negative, or zero?

• Positive

• Negative

• Zero

4 Determine the value of the discriminant and name the nature of the solution for the following:

x² + 2x - 63

Remember: b² - 4ac

• 256 - 2 reals - Rational

• √(-256 - 2 imaginary solutions

• √(137) - 2 reals - Irrational

• 123 - 2 reals - Rational