Question

Which of the following is a foci of the conic section with the equation x^2/16-y^2/4=1
(2squareroot5,0)
(0,2squareroot5)
(2squareroot3,0)

Answer 1

I see this is exactly like the previous problem you posted. Would you like to learn to solve these problems yourself?

Answer 2

yes !

Answer 3

The foci are c units from the center do you know that?

Answer 4

no..?

Answer 5

Well, you know that now. It is always the case. Then you have to know whether the hyperbola opens up and down or right and left. Which does this do?

Answer 6

Ok. let's approach it a slightly different way:
\[\frac{(x-h)^2}{a^2}-\frac{(y-k)^2}{b^2}=1\]

Answer 7

This is the equation of a hyperbola that opens to the right and left because the x^2 term is positive.

Answer 8

The center is (h,k)

Answer 9

a^2+b^2=c^2

Answer 10

Now can you find your foci?

Answer 11

okay i know that !

Answer 12

So you can find c?

Answer 13

And the center?

Answer 14

so it would be A !

Answer 15

right or wrong ?

Answer 16

Very good!!