Lecture 3, Friday, 8/29/08:
Section 10.4: The cross product
Topics
- Determinants (2 by 2 and 3 by 3)
- The cross product: Algebraic definition
(in terms of 3 by 3 determinants) and geometric interpretation
- Cross products of parallel vectors
- Cross products of standard basis vectors
- Properties of the cross product
(Th. 4.3, p. 819)
- Triple products: Scalar triple product and vector triple product
- Finding a vector perpendicular to two given vectors
- Computing the area of a parallelogram or a triangle
using cross products
- Computing the volume of a parallelepiped using the scalar triple product
- Testing if three given vectors are coplanar
(i.e., lie in the same plane)
- Computing the distance of a point to a line. (This will be covered
in the next lecture together with another distance formula.)
- Determining whether a given expression involving
dot and/or cross products represents a vector, scalar, or does not
makes sense. (The book does not have problems on this, so I prepared a
Problem Set. Most of these
problems I discussed in the lecture in connection with triple products.)
Read
Section 10.4. Optional: Examples 4.7 and 4.8.
Homework
Section 10.4: 1, 5, 13, 21, 47, 49, 53, 55, 57, 59.
Solutions.
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Last modified Sun 31 Aug 2008 05:38:37 PM CDT