Find the product of all x such that the expression

 

Find the product of all x such that the expression (x^2 - 4)/(x^2 - 1) is undefined.   

 

                                 x² – 4   

The expression is   ————   

                                 x² – 1   

 

When a denominator equals zero, the expression is undefined. 

 

So, in this case, it is undefined at  x = +1  

 

By the way, the denominator would factor to (x + 1)(x – 1)

Factoring would be helpful in a more complicated expression,  

but this one is simple enough it wasn't necessary. 

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