(a) Define vector product (b) Understand the properties of vector product (c)Find the area of parallelogram
Definition of The Vector Product (or Cross Product) then the vector product, denoted by is defined in terms of the expansion of the symbolic determinant as follows : If and
Geometrically, if where is the angle between is a unit vector in the direction perpendicular to the plane containing andand is defined as
To determine the direction of use the right-hand rule, where the fingers turn from to and the thumb points in the direction of
By referring to the above diagram, we note that
Example 1 Hence prove thatis perpendicular to the vector
Solution
From the previous lesson, we know that is perpendicular to
The properties of Vector Product
AB C D
Example 2 Solution
Example 3
Solution
Example 4
Solution
(b) A D CB ( the position vector of D)
A D CB
CONCLUSION 1. The Vector Product (Or Cross Product) 2. The Angle Between Two Vectors 3. The Area of a parallelogram if given 2 side vectors