ParametricPlot3D (Built-in Mathematica Symbol)

ParametricPlot3D[{f_x, f_y, f_z}, {u, u_min, u_max}] produces a three-dimensional space curve parametrized by a variable u which runs from u_min to u_max. ...

Sum (Built-in Mathematica Symbol)

Sum[f, {i, i_max}] evaluates the sum \[Sum]i = 1 i_max f. Sum[f, {i, i_min, i_max}] starts with i = i_min. Sum[f, {i, i_min, i_max, di}] uses steps d i. Sum[f, {i, {i_1, i_2, ...