Question

For problems 29 - 31 the graph of a quadratic function y=ax^2 + bx + c is shown. Tell whether the discriminant of ax^2 + bx + c = 0 is positive, negative, or zero.

Answer 1

29) discriminant is positive

30) discriminant is 0

31) discriminant is negative

Explanation:

the graph of a quadratic function y=ax^2 + bx + c is shown. Tell whether the discriminant of ax^2 + bx + c = 0 is positive, negative, or zero.

In the graph of question number 29 we can see that the graph intersects the x axis at two points

so the equation has 2 solutions.

When the equation has two solution then the discriminant is positive

In the graph of question number 30 we can see that the graph intersects the x axis at only one point

so the equation has only 1 solution.

When the equation has only one solution then the discriminant is equal to 0

In the graph of question number 30 we can see that the graph does not intersects the x axis

so the equation has 2 imaginary solutions.

When the equation has two imaginary solutions then the discriminant is negative