EXPLANATION
Given the equation
(b)

First, we need to find the vertex applying the following formula:
The vertices (h+a, k), (h-a,k) are the two bending points of the hyperbola with center (h,k) and semi-axis (a,b)
Calculate hyperbola properties:
Hyperbola standard equation:

Rewrite 9x^2 -y^2 = 9 in the form of a standard hyperbola equation:
Divide by coefficient of square terms: 9

Divide by coefficient of square terms: 16

Refine:

Rewrite in standard form:

Therefore, hyperbola properties are:
(h,k) = (0,0) , a=4, b=3
Refine:
(4,0), (-4,0)
Now we need to compute the foci:
For a right-left faccing hyperbola, the foci are defined as (h+c,k), (h-c,k), where c= sqrt(a^2+b^2) is the distance from the center (h,k) to a focus.
Computing c (we have previously calculated a=4 and b=3):
![c=\sqrt[]{4^2+3^2}=\sqrt[]{16+9}=\sqrt[]{25}=5](https://img.qammunity.org/2023/formulas/mathematics/college/k7vukrrh3ff6voucba041kwjfjlr0bim8k.png)
Refine:
Foci: (5,0), (-5,0)
Next, we need to find the asymptotes:
The asymptotes are the lines the hyperbola tends to at +- infinite
For right-left hyperbolas the asymptotes are:

Substituting terms:

Refine:

Now, we need to find the vertices:
The endpoints are:
(4,0) , (-4,0)
Now, we need to find the center:
