Hi everyone,

How do I write this equation in the standard form and then graph it. I don't how I could get a standard circle or a hyperbola equation from the following. I am to graph the equation after writing it but I'm sure I can if I can write it in the correct standrd form. Here it is.

9x^2 - y^2 = -16

Thanks

2. Originally Posted by coopsterdude
Hi everyone,

How do I write this equation in the standard form and then graph it. I don't how I could get a standard circle or a hyperbola equation from the following. I am to graph the equation after writing it but I'm sure I can if I can write it in the correct standrd form. Here it is.

9x^2 - y^2 = -16

Thanks
You can solve equation for $y$:
$\begin{array}{l}
9x^2 - y^2 = - 16 \\
y^2 = 9x^2 + 16 \\
y = \sqrt {9x^2 + 16} \\
\end{array}
$

Then you can graph function: $f(x) = \sqrt {9x^2 + 16}$

Here is graph:

3. Originally Posted by OReilly
You can solve equation for $y$:
$\begin{array}{l}
9x^2 - y^2 = - 16 \\
y^2 = 9x^2 + 16 \\
y = \sqrt {9x^2 + 16} \\
\end{array}
$

Then you can graph function: $f(x) = \sqrt {9x^2 + 16}$

Here is graph:
Note though that when you take the square root you have to provide BOTH possibilities: + and -:
$y = \pm \sqrt{9x^2+16}$

-Dan

4. Originally Posted by topsquark
Note though that when you take the square root you have to provide BOTH possibilities: + and -:
$y = \pm \sqrt{9x^2+16}$

-Dan
Yes, minus for me...