Ask your own question, for FREE!
Mathematics 15 Online
OpenStudy (anonymous):

Find the vertices and foci of the hyperbola with equation

OpenStudy (anonymous):

OpenStudy (anonymous):

@electrokid Can you help?

OpenStudy (anonymous):

@hartnn

OpenStudy (anonymous):

1) what type of an algebraic curve does it look like?

OpenStudy (anonymous):

oh, its give, a hyperbola

OpenStudy (anonymous):

Yes a hyperbola

OpenStudy (anonymous):

that canonical form gives you (h,k) and a, b

OpenStudy (anonymous):

Yes, but how do I know whether the hyperbola is a vertical or horizontal one?

OpenStudy (anonymous):

is a^2 bigger or b^2

OpenStudy (anonymous):

and what is "-ve" x^2 or y^2

OpenStudy (anonymous):

a^2

OpenStudy (anonymous):

since x is +ve and y is subtracted, we have x^2-y^2=1

OpenStudy (anonymous):

so, the axis of the hyperbola is "x" axis

OpenStudy (anonymous):

so, this is |dw:1364316251534:dw|

OpenStudy (anonymous):

not numbers there :)

OpenStudy (anonymous):

but you got the idea?

OpenStudy (anonymous):

Oh ok

OpenStudy (anonymous):

So it's horizontal :)

OpenStudy (anonymous):

yep

OpenStudy (anonymous):

if y^2 was positive, "y" axis would be the axis of the hyperbola

OpenStudy (anonymous):

Can you help me find the final answer, I keep trying but I'm getting answers that are not in any of the answer choices? @electrokid

OpenStudy (anonymous):

@electrokid

OpenStudy (anonymous):

(h,k)=(3,-4) \(c = \sqrt{a^2+b^2}=\sqrt{9+16}=5\) foci = \((h\pm c,k)=(3\pm5,-4) =(-2,-4) and (8,-4)\)

OpenStudy (anonymous):

seems like there is only one such option

OpenStudy (anonymous):

What?

OpenStudy (anonymous):

did you get the foci?

OpenStudy (anonymous):

No

OpenStudy (mertsj):

Do you still need help with this problem?

OpenStudy (anonymous):

Yes, please!

OpenStudy (mertsj):

Should we just start over or what?

OpenStudy (anonymous):

If we can start over, with a detailed explanation, that would be really great. Thanks :)

OpenStudy (mertsj):

You can get a lot of information about a hyperbola from its equation.

OpenStudy (anonymous):

Yes

OpenStudy (anonymous):

h, k, a, b

OpenStudy (mertsj):

The center is (h,k)

OpenStudy (mertsj):

The number below the positive term is a^2

OpenStudy (mertsj):

The number below the negative term is b^2

OpenStudy (anonymous):

So in this case, is (h,k)= (3, -4) and is a^2= 9 and b^2= 16 ?

OpenStudy (mertsj):

For a hyperbola, the relationship between a, b, and c is a^2+b^2=c^2

OpenStudy (anonymous):

Yes

OpenStudy (mertsj):

You're just about right. You have the center right but it is the x term that is positive and the y term is negative so a^2=16 and b^2=9

OpenStudy (mertsj):

The reason that a is so important is that the vertices are a units to the right and a units to the left of the center.

OpenStudy (mertsj):

Are you with me?

OpenStudy (anonymous):

Yes

OpenStudy (mertsj):

So if a^2 = 16, then a = ?

OpenStudy (anonymous):

So once I have the center, a (which is 4), b (which is 3), and c (which I believe is 5?), how do I use these to calculate the foci and vertices?

OpenStudy (mertsj):

So yes, a is 4. The vertices are "a" units to the right and "a" units to the left of the center.

OpenStudy (mertsj):

The center is (3,-4) . What point is 4 units to the right of (3,-4) ?

OpenStudy (anonymous):

(7, -4)

OpenStudy (anonymous):

oh

OpenStudy (anonymous):

and (-1, -4) to the left

OpenStudy (mertsj):

Very good. So now you know the vertices.

OpenStudy (anonymous):

Yes, foci next

OpenStudy (mertsj):

Now...the focal points. You correctly found that c is 5. That is important because the focal points are "c" units to the right and "c" units to the left of the center. So can you find the focal points?

OpenStudy (anonymous):

So... (8, -4) and (-2, -4) ?

OpenStudy (mertsj):

Very good.

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!