# Graphing problem.

• May 27th 2010, 03:00 PM
njnest214
Graphing problem.
I have to graph -4/x-4 and then find the domain, range, and if it is a function or not. I know how to do the ones with 1 as the numerator, but not -4. I have to do this by hand by the way. Any help is greatly appreciated!
• May 27th 2010, 03:44 PM
pickslides
This one? $y = \frac{-4}{x-4}$
• May 27th 2010, 03:56 PM
njnest214
Yea like that
• May 27th 2010, 04:21 PM
skeeter
first graph the "parent" $y = \frac{1}{x-4}$ ... note that the $-4$ factor does two transformations to the parent graph.

1. reflect over the x-axis

2. vertical stretch by a factor of 4.

see the graphs below ...
• May 27th 2010, 04:23 PM
pickslides
The -4 in the numerator, '-' is a reflection in the x-axis with a dilation factor of 4.

To find the domain and range you need to determine the asymptotes.

This is where the relation is not defined. Do you know how to find that?

Hint: The denominator cannot be zero.
• May 27th 2010, 04:46 PM
njnest214
Ok thanks so much guys..
I got
D: x can't equal 4
R: y can't equal 0
Function

Is that right?
• May 27th 2010, 04:56 PM
pickslides
Quote:

Originally Posted by njnest214
D: x can't equal 4
R: y can't equal 0

Yep

Quote:

Originally Posted by njnest214
O
Function

Is that right?

Why? How did you conclude this?
• May 27th 2010, 04:59 PM
njnest214
Quote:

Why? How did you conclude this?
Vertical Line Test?