Alpha must be a positive number, but it could be zero, in that case, it means that the Ridge regression is equivalent to the linear regression.
Please, review correct answer!
I guess “non-negative” would be more accurate. Thanks for the feedback 
Alpha must be a positive number, but it could be zero, in that case, it means that the Ridge regression is equivalent to the linear regression.
Please, review correct answer!
I guess “non-negative” would be more accurate. Thanks for the feedback