All Algebra II Resources
Example Questions
Example Question #461 : Intermediate Single Variable Algebra
A baseball that is thrown in the air follows a trajectory of , where is the height of the ball in feet and is the time elapsed in seconds. How long does the ball stay in the air before it hits the ground?
Between 2 and 2.5 seconds
Between 4 and 4.5 seconds
Between 3.5 and 4 seconds
Between 3 and 3.5 seconds
Between 2.5 and 3 seconds
Between 3 and 3.5 seconds
To solve this, we look at the equation .
Setting the equation equal to 0 we get .
Once in this form, we can use the Quadratic Formula to solve for .
The quadratic formula says that if , then
.
Plugging in our values:
Therefore or and since we are looking only for positive values (because we can't have negative time), 3.4375 seconds is our answer.
Example Question #4 : Quadratic Formula
Use the quadratic formula to solve the following equation.
First we want to put the equation into standard form; we do this by making sure the equation is = 0, so let's subtract 4 from both sides.
We could go straight to the quadratic formula from here, but quadratics are always easier to solve if we eliminate Greatest Common Factors first. In this case the GCF is 4 so let's divide both sides by 4.
Now we can compare against the standard form to find a, b, and c.
By pattern matching, we see that a = 1, b = -3, and c = 4. Now we substitute into the quadratic formula.
We can evaluate the square root of a negative number by factoring out the square root of -1 and calling it the imaginary number i. This gives our answer.
Example Question #2 : Quadratic Formula
Use the quadratic formula to solve the following equation:
Since the equation is already in standard form, we can compare it to the general version of standard form to find a, b, and c.
By pattern matching it is clear that a = 2, b = 4, and c = -3. Now we can substitute into the quadratic formula.
Recall that when subtracting a negative number [as in - 4(2)(-3)], the result is addition:
Combine terms and simplify the radical:
Now eliminate common factors to reduce to lowest terms.
Example Question #2 : Quadratic Formula
Use the quadratic formula to find the solutions of the following equation:
We begin by designating values of a, b and c by comparing the equation to the standard form.
By pattern matching it is clear that a = 2, b = -3, and c = -5. We can now substitute into the quadratic formula:
Take note that in the two cases where negatives/minus signs are multiplied together [-(-3) and -4(2)(-5)], they bceome positive:
Now we simplify and evaluate.
Note that in the previous step we listed the subtraction instance first, as that instance yields the smaller number and it is usually convenient to start sets with smaller numbers first.
Example Question #6 : Quadratic Formula
Solve for . Use the quadratic formula to find your solution. Use a calculator to estimate the value to the closest hundredth.
and
and
No solution
and
and
No solution
Recall that the quadratic formula is defined as:
For this question, the variables are as follows:
Substituting these values into the equation, you get:
Since you have to take the square root of a negative number, this means that there are no real solutions.
Example Question #3 : Quadratic Formula
Solve for . Use the quadratic formula to find your solution. Use a calculator to estimate the value to the closest hundredth.
and
and
and
and
No solution
and
Recall that the quadratic formula is defined as:
For this question, the variables are as follows:
Substituting these values into the equation, you get:
Use a calculator to determine the final values.
Example Question #8 : Quadratic Formula
Solve for . Use the quadratic formula to find your solution. Use a calculator to estimate the value to the closest hundredth.
and
and
and
No solution
and
and
Recall that the quadratic formula is defined as:
For this question, the variables are as follows:
Substituting these values into the equation, you get:
Use a calculator to determine the final values.
Example Question #11 : Quadratic Formula
Solve for . Use the quadratic formula to find your solution. Use a calculator to estimate the value to the closest hundredth.
and
No solution
and
and
and
and
Recall that the quadratic formula is defined as:
For this question, the variables are as follows:
Substituting these values into the equation, you get:
Separate this expression into two fractions and simplify to determine the final values.
Example Question #471 : Intermediate Single Variable Algebra
Solve for . Use the quadratic formula to find your solution. Use a calculator to estimate the value to the closest hundredth.
and
and
and
No solution
and
and
Recall that the quadratic formula is defined as:
For this question, the variables are as follows:
Substituting these values into the equation, you get:
Separate this expression into two fractions and simplify to determine the final values.
Example Question #471 : Intermediate Single Variable Algebra
Solve the quadratic equation with the quadratic formula.
Based on the quadratic equation:
,
, , and
Given the quadratic formula:
We have:
Simplfying,