answersLogoWhite

0


Best Answer

If the quadratic equation:ax^2 + bx + c has discriminant d

then its roots are x1 = [-b - sqrt(d)]/2a and x2 = [-b + sqrt(d)]/2a


If d > 0 then sqrt(d) is real and non-zero. As a result x1 and x2 are real and distinct.

If d = 0 then sqrt(d) = 0 and so x1 = x2 and both are real.

If d < 0 the sqrt(d) is imaginary so x1 and x2 form a complex conjugate pair.

User Avatar

Wiki User

βˆ™ 9y ago
This answer is:
User Avatar

Add your answer:

Earn +20 pts
Q: Why does a discriminant in a quadratic function work?
Write your answer...
Submit
Still have questions?
magnify glass
imp
Related questions

What is the discriminant of a quadratic function?

The form of the quadratic is ax2+bx+c, so the discriminant is b2-4ac.


What determines if a quadratic function has no x-intercepts?

If the quadratic function is written as ax2 + bx + c, then it has no x-intercepts if the discriminant, (b2 - 4ac), is negative.


How do you know if a quadratic function is factorrable or not?

If its discriminant is less than zero it can't be factored.


Why does the discriminant determine the number and type of the solutions for a quadratic equation?

A quadratic equation is wholly defined by its coefficients. The solutions or roots of the quadratic can, therefore, be determined by a function of these coefficients - and this function called the quadratic formula. Within this function, there is one part that specifically determines the number and types of solutions it is therefore called the discriminant: it discriminates between the different types of solutions.


How do you find the discriminant of a function?

To find the discriminant of a quadratic function, first express it in descending powers, thusax^2 + bx + c = 0 where a, b and c are real and a is non-zero.Then the discriminant is b^2 - 4ac


How many discriminant did this quadratic equation have -4j2 3j-280?

A quadratic equation has one discriminant.


Could there be a quadratic function that has an undefined axis of symmetry?

Yes and this will happen when the discriminant of a quadratic equation is less than zero meaning it has no real roots.


How many times will the graph of a quadratic function cross or touch the x axis if the discriminant is zero?

Once.


What are quadratic equations with real roots?

If the discriminant of the quadratic equation is zero then it will have 2 equal roots. If the discriminant of the quadratic equation is greater than zero then it will have 2 different roots. If the discriminant of the quadratic equation is less than zero then it will have no roots.


If the discriminant of a quadratic equation is -4 how many solutions does the equation have?

If the discriminant of a quadratic equation is less then 0 then it will have no real solutions.


What is the definition of quadratic discriminant?

The discriminant of the quadratic equation: y = ax^2 + bx + c is b^2 - 4ac


What a short example of a maximum of quadratic function?

A quadratic of the form ax2 + bx + c has no maximum if a &gt; 0: it gets infinitely large. If a = 0 then it is not a quadratic. If a &lt; 0 then the quadratic does have a maximum, and it is -D/4a where D is the discriminant = b2 - 4ac