What is logistic Regression ?
Logistic regression is also a supervised machine learning algorithm, that outputs the probability of a discrete outcome given an input variable.
So unlike a linear regression whose outcome is a continous variable. The logistic regression outputs a discrete value. Due to this it is usally it is used in classification modelling. Lets look at logistic regression and why does it has the term regression in it.
With linear regression we find the line which minimizes the sum of the squares of the residuals. We can use the residuals to calculate R2. Logistic regression does not use the concept of residuals
There are two condition a function should satisfy to work as a binary classifier. the probability should be greater than 0 and less than 1
we have an exponential function which can make it always greater than 0 how about less than one , we know that any number divide by a number greater than that number will always be less than zero