If u {\displaystyle u} is the parameter, and k i {\displaystyle k_{i}} is the i {\displaystyle i} th knot, we can write the functions f {\displaystyle f} and g {\displaystyle g} as f i , n ( u ) = u − k i k i + n − k i {\displaystyle f_{i,n}(u)={\frac {u-k_{i}}{k_{i+n}-k_{i}}}} and g i , n ( u ) = 1