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Domain of a function ? (1 Viewer)

justem

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Hey guys just a quick question, what's the domain of this function?? I've been told it's 2<_ X <_ 3 but then I distinctly remember my teacher saying that it was X>_ 3? Explanations as well please!! Thank you ^_^

 

iBibah

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The domain is just what values of x the function is defined for. So if there is a value of x that gives an "undefined" value of why then its not part of the domain.

Just think about what values of x would make the parts under the square root a negative (which isn't defined/possible).

So if your teacher said x>3, test a value (say 4) and see what happens. it would be sqrt(2) - sqrt(-1) which isn't possible.

But a value less than 2 would make the first part a square root of a negative number.

So we need a number greater than 2 and less than 3.

Hence the answer you've been told.
 

justem

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Ok thank you so much!! I actually understand that explanation, it was just confusing because I was hearing two different things , thanks :)
 

Squar3root

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Lol? If the 10 was in the domain (from what your teacher is telling you) then the 2nd expression will become imaginary.

@iBibah This isn't hsc English where you can Bullshit
 

iBibah

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Well, to be fair, it's actually:

yeh true didnt really think to put in the specifics, i just thought she misunderstood the concept of domain.

Lol? If the 10 was in the domain (from what your teacher is telling you) then the 2nd expression will become imaginary.

@iBibah This isn't hsc English where you can Bullshit
 

flyingmwa

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Hey guys just a quick question, what's the domain of this function?? I've been told it's 2<_ X <_ 3 but then I distinctly remember my teacher saying that it was X>_ 3? Explanations as well please!! Thank you ^_^

Didnt I tell u the answer during bio?
 

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