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November 17th, 2014, 06:06 PM   #1
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Smile How do get the range of this function?

Given G: [1,3) -> R, g(x) = 5 - x^3

The answer to range of this function is (-22,4]

How to do I get that?
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November 17th, 2014, 06:08 PM   #2
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Quote:
Originally Posted by KaiL View Post
Given G: [1,3) -> R, g(x) = 5 - x^3

The answer to range of this function is (-22,4]

How to do I get that?
Have you tried graphing it yet?

Otherwise you can take the derivative and see if you have any relative max/mins in the domain.

-Dan
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November 17th, 2014, 06:30 PM   #3
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[URL=https://imageshack.com/i/p8LIA6cPp]

This is the graph for the function.

The Question said that G has a domain from 1 to 3 as given from G: [1,3) so the value I can get is 1 and 2. I try subbing this value to the function but it doesnt get the answer as the book. I tried this method before and it works for another question. I am not really not sure how to go about doing this question
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November 17th, 2014, 07:22 PM   #4
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g(x) = 5 - x³, g'(x) = -3x², so g(x) is strictly decreasing over [1, 3). That means we can take the range as (g(3), g(1)] = (-22, 4].

Last edited by greg1313; November 17th, 2014 at 07:28 PM.
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