Business Math MATH 1324
North Lake College
David Katz, instructor
Section by Section List of Test Topics For Exam #3
(Chapters 3 and 4)
The exam will consist of 11 free response questions from this list of
32 topics from your homework sections.
This unit focuses on certain types of business
applications: investments, resource allocation, revenue, profit, etc. Review
these types of word problems in the homework when studying for this exam.
There will be 3-4 word problems on the test.
-
(3-1) Know when matrix addition and subtraction is
defined (both matrices must have dimensions n x m)
- (3-1) Add or subtract two matrices
- (3-1) Multiply a matrix by a scalar (constant)
- (3-1) Identify an element of a matrix by the appropriate
subscripts (e.g., a12 or b43,
etc.)
- (3-1) Translate a word problem into matrices using
matrix addition, subtraction, and/or scalar multiplication
- (3-2) Know when matrix multiplication is defined (If the
first matrix is n x m, then the second must be m x p)
- (3-2) Describe the dimensions of the product of matrix
multiplication before multiplying (n x m by m x p
=> n x p)
- (3-2) Know that matrix multiplication is not commutative
(i.e., [A] x [B] does not always = [B] x [A])
- (3-2) Translate a word problem into matrices using
multiplication of matrices
- (3-3) Write an n x n identity matrix using
rows of 1s and 0s in the appropriate places
- (3-3) Know that inverse matrices are only
possible for square matrices (n x n)
- (3-3) Square matrices that do not have inverses are
called singular matrices
- (3-3) Use augmented matrices and the technique of
reduced row echelon form to compute an inverse matrix by hand
- (3-3) Use your calculator to compute the inverse of a
matrix
- (3-3) Know that in this section, [A] refers to a square
matrix for the coefficients of a system
- (3-3) Know that in this section, [X] refers to a column
matrix for the variables of a system
- (3-3) Know that in this section, [B] refers to a column
matrix for the constants of a system
- (3-3) Write a system of equations as a system of
matrices of the form [A][X] = [B]
- (3-3) Use inverse matrices to solve systems of matrices
of the form [A][X] = [B]
- (3-3) Translate a word problem into a system of matrices
of the form [A][X] = [B]
- (4-1) Graph the feasible region (solution set) to
a system of linear inequalities
- (4-1) Shade the feasible region appropriately so that it
can be easily identified
- (4-1) Know that some solution sets are bounded; others
are unbounded
- (4-1) Know when to use a solid line or dashed line when
graphing the solution set
- (4-1) Give the exact coordinates for all corner points
(vertices) of the solution set on the graph
- (4-1) Label all essential parts of your graph: corner
points, axes, lines, feasible region, etc.
- (4-2) Know the Fundamental Theorem of Linear Programming
(p.205)
- (4-2) Optimal solutions can be found at the corner
points for bounded feasible regions
- (4-2) Identify the objective function (usually a profit
or cost function) for a system of linear inequalities
- (4-2) Decide if you have to minimize or maximize the
objective function
- (4-2) Test the corner points to look for minimum or
maximum values of the objective function
- (4-2) Translate a word problem into a system of
inequalities with an objective function
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