Identify denominator: Identify the denominator of the fraction in the function to determine the value for which the function is undefined.y = x−91 - 9The denominator of the fraction is x−9.
Set denominator to zero: Set the denominator equal to zero to find the value of x that cannot be used in the function.x−9=0Solve for x to find the excluded value.
Solve for excluded value: Add 9 to both sides of the equation to isolate x.x−9+9=0+9x=9The excluded value is 9, as this would make the denominator zero, which is undefined in real numbers.
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