For what real values of a is the expression (a + 3)/(a^3 - a) undefined? List your answers in increasing order separated by commas.

When the denominator is = 0 it is undefined

a^3 - a = 0

a^3 = a

a^2 = a

a = ±1

This is when the expression has to equal (a + 3)/0

a^3 - a = 0 = a(a+1)(a-1)

So it's undefined when a is -1 and 1.

-Vinculum

It's also undefined when a = 0,