All Algebra II Resources
Example Questions
Example Question #2 : Discriminants
What is the discriminant for the function ?
Given that quadratics can be written as . The discriminant can be found by looking at or the value under the radical of the quadratic formula. Using substiution and order of operations we can find this value of the discriminant of this quadratic equation.
Example Question #2 : Discriminants
How many solutions does the quadratic have?
no solutions
immaginary solutions
real solution
real solution and immaginary solution
real solutions
real solutions
The discrimiant will determine how many solutions a quadratic has. If the discriminant is positive, then there are two real solutions. If it is negative then there are two immaginary solutions. If it is equal to zero then there is one repeated solution.
Given that quadratics can be written as . The discriminant can be found by looking at or the value under the radical of the quadratic formula. Using substiution and order of operations we can find this value of the discriminant of this quadratic equation.
The discriminant is positive; therefore, there are two real solutions to this quadratic.
Example Question #1 : Discriminants
How many real roots are there to the following equation:
None of the above
This is using the discriminant to find roots. The discriminant as you recall is
If you get a negative number you have no real roots, if you get zero you have one, and if you get a positive number you have two real roots.
So plug in your numbers:
Because you get a negative number you have zero real roots.
Example Question #11 : Discriminants
Use the discriminant to determine the number of unique zeros for the quadratic:
1 root
2 roots
0 roots
3 roots
1 root
The discriminant is part of the quadratic formula. In the quadratic formula,
The discriminant is the term:
If the discriminant is 0, there is only one real solution. This would be:
, since the our discriminant is gone.
If the discriminant is a positive number, then we have two real roots, the usual form of the quadratic equation:
Finally, if the discriminant is negative, we would be taking the square root of a negative number. This will give us no real zeros.
Plugging the numbers into the discriminant gives us:
The discriminant is zero, so there is only one root,
Example Question #261 : Intermediate Single Variable Algebra
Use the discriminant to determine the number of real roots the function has:
It is impossible to determine
The function has one real root
The function has no real roots
The function has two real roots
The function has two real roots
Using the discriminant, which for a polynomial
is equal to
,
we can determine the number of roots a polynomial has. If the discriminant is positive, then the polynomial has two real roots. If it is equal to zero, the polynomial has one real root. If it is negative, then the polynomial has two roots which are complex conjugates of one another.
For our function, we have
,
so when we plug these into the discriminant formula, we get
So, our polynomial has two real roots.
Example Question #13 : Discriminants
Find the discriminant of the following quadratic equation:
The discriminant is found using the following formula:
For the particular function in question the variable are as follows.
Therefore:
Example Question #262 : Intermediate Single Variable Algebra
Determine the number of real roots the given function has:
Two real roots
No real roots
None of the other answers
One real root
One real root
To determine the amount of roots a given quadratic function has, we must find the discriminant, which for
is equal to
If d is negative, then we have two roots that are complex conjugates of one another. If d is positive, than we have two real roots, and if d is equal to zero, then we have only one real root.
Using our function and the formula above, we get
Thus, the function has only one real root.
Example Question #15 : Discriminants
What is the discriminant of ?
Write the formula for the discriminant. This is the term inside the square root of the quadratic formula.
The given equation is already in the form of .
Substitute the terms into the formula.
The answer is:
Example Question #16 : Discriminants
Determine the discriminant of the following parabola:
The polynomial is written in the form , where
Write the formula for the discriminant. This is the term inside the square root value of the quadratic equation.
Substitute all the knowns into this equation.
The answer is:
Example Question #17 : Discriminants
Describe the roots of this quadratic equation by evaluating the discriminant:
Because the discriminant is positive, this quadratic will have two distinct and real solutions.
None of these
Because the discriminant is negative, this quadratic will have two complex roots.
Because the discriminant is negative, it will have two distinct and real solutions.
Because the discriminant equals 0, the quadratic will have one repeated solution.
Because the discriminant is negative, this quadratic will have two complex roots.
We use the quadratic formula to evaluate the types of roots, but it is not necessary to solve the whole equation. Simply look at the discriminant or square root part.
Plug in the correct numbers in the discriminant and simplify. Do not take the square root.
Since will be negative, this equation will have two complex solutions.
Discrimant<0= Two complex solutions
Discriminant>0= Two distinct and real solutions
Discriminant=0 = One repeated solution