excluded values
- Thread starter aj923
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pka
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I assume the question relates to domain issues.
Basically when using real numbers there are two operations that have no definitions.
First, we cannot allow an even root of a negative number, because the even power of any number is not negative.
Second, we do not allow division by zero, because that makes all numbers equal.
So if you have this expression \(\displaystyle \L f(x) = \frac{{\sqrt[4]{{x + 4}}}}{{x - 2}}\)
then we must exclude any number less than –4 and we must exclude 2.
Basically when using real numbers there are two operations that have no definitions.
First, we cannot allow an even root of a negative number, because the even power of any number is not negative.
Second, we do not allow division by zero, because that makes all numbers equal.
So if you have this expression \(\displaystyle \L f(x) = \frac{{\sqrt[4]{{x + 4}}}}{{x - 2}}\)
then we must exclude any number less than –4 and we must exclude 2.
D
Deleted member 4993
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Same principle.
y=0 and z=-5 are not included (since those make the denominator = 0 making the expression "undefined".
y=0 and z=-5 are not included (since those make the denominator = 0 making the expression "undefined".