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Chapter 4, "Vector Operations"Vector Versus ScalarScalar = magnitude only. Vector = magnitude + direction. DisplacementDisplacement = final position “ initial position. D x = x f “ x i Polar CoordinatesVector
where is the magnitude of A and q is the direction. Cartesian Coordinates (Components)Vector where is one unit in the x direction and is one unit in the y direction. Converting from Polar to Cartesian CoordinatesFor vector ,
where a 1 = cos q and a 2 = sin q . Converting from Cartesian to Polar CoordinatesFor vector , . Cartesian Coordinates (Components) in 3DVector where is one unit in the x direction, is one unit in the y direction, and is one unit in the z direction. Commutative Law of Vector AdditionA + B = B + A for any vectors A and B. Adding 2D Vectors Numerically
for vectors and . Adding 3D Vectors Numerically
for vectors and . Subtracting Vectors Numerically
for vectors and . Subtracting 3D Vectors Numerically
for vectors and . Scalar Multiplication in Polar Coordinates
for any scalar c and vector . Scalar Multiplication in Cartesian Coordinates
for any scalar c and vector . Normalizing a 2D Vector
for any vector A = [ a 1 a 2 ]. Normalizing a 3D Vector
for any vector A = [ a 1 a 2 a 3 ]. Dot Product in 2DA B = a 1 b 1 + a 2 b 2 for any 2D vectors A = [ a 1 a 2 ] and B = [ b 1 b 2 ]. Dot Product in 3DA B = a 1 b 1 + a 2 b 2 + a 3 b 3 for any 3D vectors A = [ a 1 a 2 a 3 ] and B = [ b 1 b 2 b 3 ]. Perpendicular CheckIf A B = 0, A B. Positive or Negative Dot ProductIf A B < 0 (negative), q > 90 ° If A B > 0 (positive), q < 90 ° where q is the angle between vectors A and B. Angle Between Two Vectors
where q is the angle between vectors A and B. Cross-ProductA x B = [( a 2 b 3 “ a 3 b 2 ) ( a 3 b 1 “ a 1 b 3 ) ( a 1 b 2 “ a 2 b 1 )] for any two vectors A = [ a 1 a 2 a 3 ] and B = [ b 1 b 2 b 3 ]. Perpendicular VectorsA x B is perpendicular to both vectors A and B. Cross-Product Is Not CommutativeA x B B x A In fact, A x B = “(B x A) for any two 3D vectors A and B. Surface NormalSurface normal = for any two 3D vectors A and B. Angle Between Two Vectors
for any two 3D vectors A and B. |
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