A normal derivative is a directional derivative taken in the direction normal (that is, orthogonal) to some surface in space, or more generally along a normal vector field orthogonal to some hypersurface. See for example Neumann boundary condition. If the normal direction is denoted by, then the directional derivative of a function ƒ is sometimes denoted as . In other notations
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Famous quotes containing the words normal and/or derivative:
“A normal adolescent is so restless and twitchy and awkward that he can mange to injure his knee—not playing soccer, not playing football—but by falling off his chair in the middle of French class.”
—Judith Viorst (20th century)
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—Henry David Thoreau (1817–1862)