Algebra II : Quadratic Equations and Inequalities

Study concepts, example questions & explanations for Algebra II

varsity tutors app store varsity tutors android store

Example Questions

Example Question #15 : Quadratic Formula

The height of a kicked soccer ball  can be modeled with the equation

,

where the height  is given in meters and  is the time in seconds. At what time(s) will the ball be 2 meters off the ground?

 

Possible Answers:

 seconds

 seconds

or

 seconds

 seconds 

or

 seconds

 seconds

 seconds

Correct answer:

 seconds 

or

 seconds

Explanation:

Set up the equation to solve for the time  when the height  is at 2 meters:

Now put the equation into quadratic form  so that we can solve it using the quadratic formula

.

The quadratic equation is

,

where ,  , and .

Solving for  gives us two possible values,

 seconds

or

 seconds.

 

 

 

Example Question #11 : Quadratic Formula

Solve for .

Possible Answers:

Correct answer:

Explanation:

When applying the quadratic formula, the discriminant (portion under the square root) is negative and so there are no real roots of the equation shown.

Example Question #475 : Intermediate Single Variable Algebra

Solve for x

Possible Answers:

Correct answer:

Explanation:

Once the square is multiplied out and the equation simplified, it yields , a good time for the quadratic formula,  where a, b, c are the coefficients of the polynominal in descending order. Plug in a=1, b=6, c=6, and it yields , multiply out the square root and it yields .

Example Question #476 : Intermediate Single Variable Algebra

Using the quadratic equation, find the roots of the following expression.

Possible Answers:

No real solutions

Correct answer:

Explanation:

To find the roots of the quadratic expression, we must use the quadratic equation

Plugging in our values for , , and  (, and , respectively) we get the equation:

First, let's simplify the radical:

which becomes

or

Now that we've simplified the radical, we need to solve for both solutions:

and

Therefore, the roots of this quadratic expression are  and .

Example Question #311 : Quadratic Equations And Inequalities

Find the roots of the following equation using the quadratic formula:

Express in simplest form.

Possible Answers:

Correct answer:

Explanation:

Remember the quadratic equation. For any quadratic polynomial, , the roots of the function are given by:

In this situation, we have , so .

Substituting into the formula, we get the roots at:

Simplifying gives us:

.

Example Question #2 : How To Use The Quadratic Function

Which of the following is the correct solution when    is solved using the quadratic equation?

Possible Answers:

Correct answer:

Explanation:

Example Question #311 : Quadratic Equations And Inequalities

Solve the equation using the quadratic formula.

Possible Answers:

Correct answer:

Explanation:

The quadratic formula is

.

Setting , ,  yields,

 

Example Question #481 : Intermediate Single Variable Algebra

Find the roots of:  

Possible Answers:

Since the quadratic cannot be factored, there are no roots.

Correct answer:

Explanation:

Identify the values of , and  in the standard form of the parabola.

Calculate the discriminant.

Since the discriminant is less than zero, the quadratic is irreducible and there are no real roots. However, there are complex roots.  Use the quadratic formula to determine the complex roots.

Example Question #482 : Intermediate Single Variable Algebra

Use the quadratic formula to find the roots of .

Possible Answers:

 and 

 and 

no solution

 and 

Correct answer:

 and 

Explanation:

The parent function of a quadratic is represented as . The quadratic formula is . In this case , and . Replacing these values into the quadratic forumula will give you the solutions to the quadratic. 

 and 

Example Question #483 : Intermediate Single Variable Algebra

Solve this quadratic equation by using the quadratic formula: 

Possible Answers:

Correct answer:

Explanation:

You must know the quadratic equation .

To plug in the right terms, recognize that polynomials in standard form are symbolized as .

Plug in the values from your equation

simplify within the radical:

Simplify the radical:

Reduce:

 

Note that this represents two values since there is a  in the equation. One is solved with an addition sign and the other is solved with a subtraction sign to yield two answers or roots where this equation crosses the x axis. 

 

Learning Tools by Varsity Tutors