Tangent Lines and Normal Vectors
(Page: 1
 2 ) Text If a parametric curve (x(t), y(t)) is differentiable at t_{0}, then (x(t), y(t)) will have a tangent line at (x(t_{0}), y(t_{0})) determined by the vector (x'(t), y'(t)).
The normal vector at t_{0}, (y '(t_{0}), x'(t_{0})), is perpendicular to the tangent line.
Demos
