# Find the natural domain of the function

1. Oct 1, 2007

### mooneh

i have this question that i dont totally get what it wants exactly so if anyone can help me understand it correctly, thx

Find the natural domain of the function algebraically,and confirm that your result is consistent with the graph produced by your graphing utility. note: set your graphing utility to radian mode when graphing trigonometric function.

for example one of the questions :
f(x) = 1/x-3

2. Oct 1, 2007

### dextercioby

Is that $$\frac{1}{x}-3$$ or $$\frac{1}{x-3}$$ ...? In both cases, are there points in $\mathbb{R}$ where the function is not defined ?

3. Oct 1, 2007

### mooneh

it's the second one

4. Oct 1, 2007

### arildno

Okay, then!

Now, what number or numbers cannot be placed in the denominator of a fraction, if any?

5. Oct 1, 2007

### mooneh

3 because then the denominator will be 0
but i dont get what the question meant abt the graphing utility...

6. Oct 1, 2007

### HallsofIvy

Staff Emeritus
Do you understand what "domain" means? It is the set of possible values for x. the "natural domain" for a formula is the set of all possible values of x for which that formula gives a value. To see what is meant by the "graphing utility", go ahead and graph the function y= 1/(x-3) on, say a graphics calculator or computer graphing program (that's the "graphing utility") and see what happens when x= 3.