# Algebraic Definition of Residuals from a Regression

#### cassetete

##### New Member
I just need a hint on how to get started on this. Any advice?

Define the residual from a regression (one independent variable) algebraically and show that:
a. the mean of the residuals is zero, and
b. the correlation of the residuals and the independent variable is zero.

Many thanks!

#### Mean Joe

##### TS Contributor
I've seen this done before here, maybe in the probability forum. Here's one thread I found: Residual sum=0