# Finding domain and Range

• Sep 23rd 2012, 02:27 PM
M670
Finding domain and Range
I don't know for some reason this question is confusing me and I can't find an example similar in my text book
domain and range of http://webwork.mathstat.concordia.ca...726f652811.png:
• Sep 23rd 2012, 02:36 PM
Plato
Re: Finding domain and Range
Quote:

Originally Posted by M670
I don't know for some reason this question is confusing me and I can't find an example similar in my text book
domain and range of http://webwork.mathstat.concordia.ca...726f652811.png:

The range is $(-6,\infty)$. What is the domain?
• Sep 23rd 2012, 02:38 PM
skeeter
Re: Finding domain and Range
You should be familiar w/ the graph of the parent function $y = \frac{1}{x^2}$. Its domain is the same as for f(x).

... what transformation has occurred to the parent function by subtracting 6 ? How does this affect the range?
• Sep 23rd 2012, 02:39 PM
M670
Re: Finding domain and Range
The domain should be all real number except where the denominator is zero
• Sep 23rd 2012, 02:43 PM
Plato
Re: Finding domain and Range
Quote:

Originally Posted by M670
The domain should be all real number except where the denominator is zero

Correct!
• Sep 23rd 2012, 02:44 PM
M670
Re: Finding domain and Range
Quote:

Originally Posted by skeeter
You should be familiar w/ the graph of the parent function $y = \frac{1}{x^2}$. Its domain is the same as for f(x).

... what transformation has occurred to the parent function by subtracting 6 ? How does this affect the range?

I believe by subtracting 6 we are getting a negative y value
• Sep 23rd 2012, 02:51 PM
M670
Re: Finding domain and Range
To represent the domain in interval notation it would be (-infinity,0) U (0, infinity)
• Sep 23rd 2012, 03:05 PM
M670
Re: Finding domain and Range
Quote:

Originally Posted by Plato
The range is $(-6,\infty)$. What is the domain?

Could you give me the steps you used to find the range
I know its the max point on the Y axis where x can effect it, so this would mean that my graph would not go past -6on the y
• Sep 23rd 2012, 03:36 PM
Plato
Re: Finding domain and Range
Quote:

Originally Posted by M670
Could you give me the steps you used to find the range
I know its the max point on the Y axis where x can effect it, so this would mean that my graph would not go past -6on the y

The range of $\frac{1}{x^2}$ is $(0,\infty)$.

The range of $\frac{1}{x^2}-6$ is $(-6,\infty)$.
• Sep 23rd 2012, 03:38 PM
M670
Re: Finding domain and Range
ahh I see said the blind man