SOLUTION: Find all numbers for which x - 1 / x^2-2x -15 is defined

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Question 156468: Find all numbers for which x - 1 / x^2-2x -15 is defined
Answer by solver91311(24713) About Me  (Show Source):
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The only way for %28x-1%29%2F%28x%5E2-2x-15%29 to be UNdefined is for the denominator to be zero, so solve x%5E2-2x-15=0 and your original rational function will be undefined for the two roots you obtain. The original rational function is then defined for all real numbers EXCEPT those two roots.