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Basics
Solving
Random Discriminant questions 1
Random Discriminant questions 2
100

What is the formula for the discriminant?

b2 - 4ac

100

Where does b2−4ac come from? 

Quadratic formula 

100

Find the discriminant  x2 + 6x - 5 = 0

x2 + 6x - 5 = 0

62 - 4(1)(-5)

= 56

It has 2 real solutions


100

How many x intercepts are there if the discriminant is equal to 0?

One solution

1 x-intercept

200

What would you use the discriminant for?

To determine the number of roots a quadratic has, 

To find the number of x-intercepts

200

What does the discriminant tells us? 

The discriminant indicates whether there are two solutions, one, or none at all  

200

Show by using the discriminant 

2x2 - 3x + 7 


0 = 2x2 - 3x + 7

-32 -4(2)(7)

= -47

So it never touches the x-axis

no x-intercept

200
Solve for discriminant

y=x2-14x+2

188

2 real solutions

2 x-intercepts

300

What's the value of the discriminant if it has no real roots?

Anything less than zero

300

What is the discriminant of 

-x2+8x=-12

112


2 Real Solutions

2 x-intercepts

300

Solve the equation 3x2=10x-9

-8

2 imaginary solutions

no x-intercept

300

Find the discriminant to find the number of x-intercepts in the function f(x) = -16x + 12 + 6x2

f(x) = 6x2 - 16x + 12

-162 - 4(6)(12)

= -32

No x-intercepts

400
What does it mean if the discriminant its zero?

1 Solution

400

Solve: 

 f(x) = 6x2+2x+1

-20 

2 Imaginary Solutions 

No x intercept


400

Find the discriminant

-3x2-6x-9=0

-72

2 imaginary solutions

no x-intercept

400

-x2+x-6

-23

2 imaginary solutions

no x-intercept

500

What type of roots does a discriminant have when it's less than zero? 

2 Imaginary Solutions

500

Solve: 

f(x)=x2-x

1 

2 real Solutions

2 x-intercepts

500
Find how the number of x-intercepts

2x2-18=0

144 

2 real solutions

2 x-intercepts

500

Find the discriminant of x2 - 4.7x + 14.8 = 0 to determine how many roots it has. 

x2 - 4.7x + 14.8 = 0

= -37.11

It has no real roots

2 imaginary solutions

no x-intercept