Precalculus : Hyperbolas and Ellipses

Study concepts, example questions & explanations for Precalculus

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Example Questions

Example Question #42 : Graphs

Find the foci of the hyperbola with the following equation:

Possible Answers:

Correct answer:

Explanation:

Recall that the standard formula of a hyperbola can come in two forms:

 and

, where the centers of both hyperbolas are .

When the term with  is first, that means the foci will lie on a horizontal transverse axis.

When the term with  is first, that means the foci will lie on a vertical transverse axis.

To find the foci, we use the following:

For a hyperbola with a horizontal transverse access, the foci will be located at  and .

For a hyperbola with a vertical transverse access, the foci will be located at  and .

For the given hypebola in the question, the transverse axis is horizontal and its center is located at .

Next, find .

The foci are then located at  and .

Example Question #43 : Graphs

Find the foci of the hyperbola with the following equation:

Possible Answers:

Correct answer:

Explanation:

Recall that the standard formula of a hyperbola can come in two forms:

 and

, where the centers of both hyperbolas are .

First, put the given equation in the standard form of the equation of a hyperbola.

Group the  terms together and the  terms together.

Next, factor out  from the  terms and  from the  terms.

From here, complete the squares. Remember to add the same amount to both sides of the equation!

Subtract  from both sides.

Divide both sides by .

Factor both terms to get the standard form for the equation of a hyperbola.

When the term with  is first, that means the foci will lie on a horizontal transverse axis.

When the term with  is first, that means the foci will lie on a vertical transverse axis.

To find the foci, we use the following:

For a hyperbola with a horizontal transverse access, the foci will be located at  and .

For a hyperbola with a vertical transverse access, the foci will be located at  and .

For the given hypebola in the question, the transverse axis is horizontal and its center is located at .

Next, find .

The foci are then located at  and .

Example Question #203 : Conic Sections

Find the foci of the hyperbola with the following equation:

Possible Answers:

Correct answer:

Explanation:

Recall that the standard formula of a hyperbola can come in two forms:

 and

, where the centers of both hyperbolas are .

First, put the given equation in the standard form of the equation of a hyperbola.

Group the  terms together and the  terms together.

Next, factor out  from the  terms and  from the  terms.

From here, complete the squares. Remember to add the same amount to both sides of the equation!

Subtract  from both sides.

Divide both sides by .

Factor both terms to get the standard form for the equation of a hyperbola.

When the term with  is first, that means the foci will lie on a horizontal transverse axis.

When the term with  is first, that means the foci will lie on a vertical transverse axis.

To find the foci, we use the following:

For a hyperbola with a horizontal transverse access, the foci will be located at  and .

For a hyperbola with a vertical transverse access, the foci will be located at  and .

For the given hypebola in the question, the transverse axis is horizontal and its center is located at .

Next, find .

The foci are then located at  and .

Example Question #111 : Understand Features Of Hyperbolas And Ellipses

Find the foci of the hyperbola with the following equation:

Possible Answers:

Correct answer:

Explanation:

Recall that the standard formula of a hyperbola can come in two forms:

 and

, where the centers of both hyperbolas are .

First, put the given equation in the standard form of the equation of a hyperbola.

Group the  terms together and the  terms together.

Next, factor out  from the  terms and  from the  terms.

Complete the squares. Remember to add the same amount to both sides of the equation!

Add  to both sides.

Divide both sides by .

Factor both terms to get the standard form of the equation of a hyperbola.

When the term with  is first, that means the foci will lie on a horizontal transverse axis.

When the term with  is first, that means the foci will lie on a vertical transverse axis.

To find the foci, we use the following:

For a hyperbola with a horizontal transverse access, the foci will be located at  and .

For a hyperbola with a vertical transverse access, the foci will be located at  and .

For the given hypebola in the question, the transverse axis is vertical and its center is located at .

Next, find .

The foci are then located at  and .

Example Question #112 : Understand Features Of Hyperbolas And Ellipses

Find the foci of the hyperbola with the following equation:

Possible Answers:

Correct answer:

Explanation:

Recall that the standard formula of a hyperbola can come in two forms:

 and

, where the centers of both hyperbolas are .

First, put the given equation in the standard form of the equation of a hyperbola.

Group the  terms together and the  terms together.

Next, factor out  from the  terms and  from the  terms.

Now we can complete the squares. Remember to add the same amount to both sides of the equation!

Add  to both sides.

Divide both sides by .

Factor both terms to get the standard form of the equation of a hyperbola.

When the term with  is first, that means the foci will lie on a horizontal transverse axis.

When the term with  is first, that means the foci will lie on a vertical transverse axis.

To find the foci, we use the following:

For a hyperbola with a horizontal transverse access, the foci will be located at  and .

For a hyperbola with a vertical transverse access, the foci will be located at  and .

For the given hypebola in the question, the transverse axis is vertical and its center is located at .

Next, find .

The foci are then located at  and .

Example Question #1781 : Pre Calculus

Find the foci of the hyperbola with the following equation:

Possible Answers:

Correct answer:

Explanation:

Recall that the standard formula of a hyperbola can come in two forms:

 and

, where the centers of both hyperbolas are .

When the term with  is first, that means the foci will lie on a horizontal transverse axis.

When the term with  is first, that means the foci will lie on a vertical transverse axis.

To find the foci, we use the following:

For a hyperbola with a horizontal transverse access, the foci will be located at  and .

For a hyperbola with a vertical transverse access, the foci will be located at  and .

For the given hypebola in the question, the transverse axis is vertical and its center is located at .

Next, find .

The foci are then located at  and .

Example Question #111 : Understand Features Of Hyperbolas And Ellipses

Find the foci of the hyperbola with the following equation:

Possible Answers:

Correct answer:

Explanation:

Recall that the standard formula of a hyperbola can come in two forms:

 and

, where the centers of both hyperbolas are .

When the term with  is first, that means the foci will lie on a horizontal transverse axis.

When the term with  is first, that means the foci will lie on a vertical transverse axis.

To find the foci, we use the following:

For a hyperbola with a horizontal transverse access, the foci will be located at  and .

For a hyperbola with a vertical transverse access, the foci will be located at  and .

For the given hypebola in the question, the transverse axis is vertical and its center is located at .

Next, find .

The foci are then located at  and .

Example Question #113 : Hyperbolas And Ellipses

Find the foci of the hyperbola with the following equation:

Possible Answers:

Correct answer:

Explanation:

Recall that the standard formula of a hyperbola can come in two forms:

 and

, where the centers of both hyperbolas are .

When the term with  is first, that means the foci will lie on a horizontal transverse axis.

When the term with  is first, that means the foci will lie on a vertical transverse axis.

To find the foci, we use the following:

For a hyperbola with a horizontal transverse access, the foci will be located at  and .

For a hyperbola with a vertical transverse access, the foci will be located at  and .

For the given hypebola in the question, the transverse axis is vertical and its center is located at .

Next, find .

The foci are then located at  and .

Example Question #1793 : Pre Calculus

Find the foci for the hyperbola with the following equation:

Possible Answers:

Correct answer:

Explanation:

Recall that the standard formula of a hyperbola can come in two forms:

 and

, where the centers of both hyperbolas are .

When the term with  is first, that means the foci will lie on a horizontal transverse axis.

When the term with  is first, that means the foci will lie on a vertical transverse axis.

To find the foci, we use the following:

For a hyperbola with a horizontal transverse access, the foci will be located at  and .

For a hyperbola with a vertical transverse access, the foci will be located at  and .

For the given hypebola in the question, the transverse axis is vertical and its center is located at .

Next, find .

The foci are then located at  and .

Example Question #112 : Understand Features Of Hyperbolas And Ellipses

Which point is one of the foci of the hyperbola ?

Possible Answers:

Correct answer:

Explanation:

To find the foci of a hyperbola, first determine a and b, and then use the relationship

In this case, the major axis is horizontal since x comes first, so and .

Solve for c: add 9 to both sides 

take the square root

Since the center is and the major axis is the horizontal one, our foci are . The only choice that works is

.

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