Finding domain and range from equation of inverse function

Quadratic equations and inequalities, variation equations, function notation, systems of equations, etc.
onmyown
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Finding domain and range from equation of inverse function

Postby onmyown » Thu Aug 04, 2011 12:19 am

Can someone please tell me the domain and range of this equation:

Image

I know the answer. It is:
The domain is all values of x that are greater than or equal to -2.
The range (y) is all real numbers.

I don't understand why though.

Shouldn't the domain be "all values of x that are greater than or equal to -3" because in the expression under the square root, the constants (2+1) equal to 3, and the number under the square root cannot be negative, therefore, x cannot be any number less than -3.

As for the range, I simply just don't understand why it can be anything.

Any help will greatly be appreciated!
thank you

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stapel_eliz
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Postby stapel_eliz » Thu Aug 04, 2011 1:27 am

I don't see how they got their answers, either. But the formatting, "x + 2 + 1", is extremely odd, which suggests that there is a typo somewhere.

Probably your best bet is to ask your instructor if this exercise statement contains any errors, pointing out the logic that you have posted here. I'll bet that, after corrections, the exercise makes a whole lot more sense! :wink:


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