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How can you solve the range and domain of an equation?math 4

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jovandave | Student, Undergraduate | eNotes Newbie

Posted January 27, 2009 at 9:56 AM via web

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How can you solve the range and domain of an equation?

math 4

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giorgiana1976 | College Teacher | (Level 3) Valedictorian

Posted January 27, 2009 at 4:18 PM (Answer #1)

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You can determine the range and domain of a given equation by setting up tabular values.

For you to make a general statement about the domain of x values and the range of the y values, you have to plug in the values for x in order to obtain values for y.

Let's analyze the next equation:

f(x)=-x^2 + 2

f(x)=0 so -x^2 + 2=0

Plugging in values for x, we will see that is no restriction concerning the domain of x values, this one being all real numbers.

On the other hand, there is a restriction for y, so the range is going to be less or equal to 2.

 

x

......

-2

-1

0

1

2

.......

f(x)

 

-2

-1

2

1

-2

 

f(x)<=2

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revolution | College Teacher | (Level 1) Valedictorian

Posted July 31, 2010 at 8:48 PM (Answer #2)

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For example, you need to find the range  of an equation, x^2+7

First, you must get the definition right. The range of the equation defines as a set of numerical values that the function (X) would used as x-values changes all the time.

You would get a range like this: X^2>=0.

Next, subtract negative 7 to both side of inequality equation so

X^2-7>=-7. This inequality equation shows that this X^2-7 would take any values that is bigger or equal to -7. So, the range would be like this  (-7 and +infinite values).

The domain of this equation would be a positive set of x-values so domain is x^2>=0, more or equal to zero.

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