Question 574911
find all numbers for which the rational expression is undefined 
x^2+17 over x^2-2x-3
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Undefined when that denominator is zero.
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Solve x^2-2x-3 = 0
Factor:
(x-3)(x+1) = 0
Undefined when x = 3 or x = -1
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Cheers,
Stan H.