Find all values of xxx for which x2+2x−3x2−1\frac{x^2 + 2x - 3}{x^2 - 1}x2−1x2+2x−3 is undefined.
x=−1,1x = -1, 1x=−1,1
x=1x = 1x=1
x=−3,1x = -3, 1x=−3,1
x=−1,3x = -1, 3x=−1,3