\(f_{w,b}(x)=wx+b\)
\(w,b\)
\(J(w,b)={1 \over 2m} \sum_{i=0}^{m-1}(f_{w,b}(x^{(i)}) - y^{(i)})^2\)
\(\underset{w,b}{minimize} J(w,b)\)
