let's take 1 / (1 + e^(-2x)) first. 1 / (1 + 1/e^(2x)) 1 / ((e^(2x) + 1) / e^(2x)) : see what i did here? i combined 1 and 1 / e^(2x) via least common denominator. **e^(2x) / (e^(2x) + 1).** now for e^(x) / (e^(x) + e^(-x)). e^(x) / (e^(x) + 1 / e^(x)) e^(x) / ((e^(2x) + 1) / e^(x)) : again, i combined the e^(x) and the 1/e^(x) via least common denominator. **e^(2x) / (e^(2x) + 1).** the expressions are equal! -slim