Hi so I've got this problem for university and I just can't see how I'm supposed to rewrite this expression: $\dfrac{\exp(\mathbf{w^{t}x} + w_{0})}{\exp{(\mathbf{w^{t}x}} + w_{0}) + 1}$ into this: $\dfrac{1}{1 + \exp(-a)}$ where $\textit{a}$ can be any value.

I first tried simplifying the expression which lead to: $1 - \dfrac{1}{1 + \exp(\mathbf{w^tx} + w_{0})}$, this almost looks like what is required, $\textit{a}$ would then obviously be: $-\mathbf{w^{t}x} + w_{0}$. But I don't really know how to get rid of the 1 at the beginning of the resulting expression, nor do I see how I could otherwise rewrite/simplify it.

Any help is appreciated.



  • Divide both the numerator and the denominator by $\exp(w^Tx + w_0)$
  • $\begingroup$ Thanks for the help, that I did not see that. (I feel dumb :P) $\endgroup$ – PEREZje Dec 8 '18 at 14:18

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.