SOLUTION: We're trying to help our grandson with 8th grade algebra. Could you explain to me what domain means.(as in find domain of the function?) Sincerely, Teresa M.

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Question 142577: We're trying to help our grandson with 8th grade algebra. Could you explain to me what domain means.(as in find domain of the function?) Sincerely, Teresa M.
Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website!
Linear equation: y = 3x + 5
Domain: all Real Numbers
Why? x is an independent variable that can take on any Real value
unless there is some reason in the equation which restricts values
of x.
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Examples of restricted domains:
y = 3/(x+2)
x cannot take the value -2 because that would make the fraction
meaningless (Note: You cannot divide by zero)
Domain: All Real Numbers except x = -2
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y = sqrt(x-3)
The x-3 cannot be negative because the square root of a negative
is not a Real Number.
So x must be greater than or equal to 3.
Domain: All Real Numbers greater than or equal to 3.
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Comment: Those examples show the primary reasons for restricting
the domain:
1st: Denominators cannot zero
2nd: You cannot take the square root of a negative.
There are other conditions that restrict the Domain of a function
but I am assuming you are dealing with fundamentals of algebra.
Cheers,
Stan H.