When {{MATH_95}}, the quantity {{MATH_96}} is negative (because {{MATH_97}}) and approaches {{MATH_98}} and the numerator is negative. This is a {{CMD_99}} form which is positive for all {{MATH_100}} sufficiently close to, but less than, {{MATH_101}}. Therefore, {{MATH_102}}. Since the two one-sided limits did not agree, {{MATH_103}} does not exist.