MATH2070 Optimization and Financial Mathematics Quiz Review
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MATH2070 Quiz Review
PART I Quiz Review
PART 1.1 Sample quiz
Question 1: The critical point of the function f(x, y) = 3x2 − 2xy + y2 + 4x + 2 is :
a) (− 1, 1)
b) (1, 1)
c) (− 1, − 1)
d) (1, − 1)
Question 2: The symmetric matrix A associated with the quadratic form is :
T 2 2 2
Q = x Ax = 2x − 8xy + 9y + 4yz + 2z + 2zx
Question 3: By completing the square determine the nature of the quadratic form :
2 2
Q = x + 6xy + 11y
a) Indefinite
b) Negative indefinite
c) Positive definite
d) Positive semi-definite
Question 4: The Hessian H of the function f(x, y) = x4 + x2 + 2xy − y2 − 4x + 4y − 4 at the point (0, 2) is :
Question 5: The eigenvalues of the matrix are:
a) - 1 & 9
b) 0 & 9
c) 1 & -9
d) -9 & 9
Question 6: Test the Hessian matrix to determine the nature of the critical point (1,1) of
2 2
f(x, y) = − 2x + 2xy − y + 2x + 1
a) A local maximum
b) A local minimum
c) A saddle point
d) Test fails
Question 7: Which is the correct Lagrangian functions for the following optimization problem?
Maximize : 2x + y − x − xy − 2y
Subject to : x + 2y ≤ 1
2 2 2
c) L = − 2x − y + x + xy + 2y + λ(x + 2y + s − 1)
d) L = − 2x + y + x2 + xy + 2y2 + λ(x + 2y + s2 − 1)
Question 8: A gambler is invited to play a simple game in which two coins are tossed. He will receive nothing if both coins show tails, or $12 if one shows heads and one shows tails, or else $60 if both coins show heads. What is the gambler's expected return in this game?
a) $19
b) $21
c) $24
d) None of the above
PART 1.2 Tutorial Questions
Question 1: The following is the final simplex tableau for a linear programming problem :
X X2 2 0 − 1 0 1 1 |
X 3 1 1 1 |
X 4 0 1 0 |
X 5 3 − 1 1 |
RHS 6 2 2 |
a) What are the non-basic variables?
b) What is the optimal value of the objective functions?
c) Identify the solution vertex (X1, X2, X3 )
Question 2: Consider the function f(x, y) = (x − 2)4 + x2 + 4y2 − 4xy, show analytically that this function has one critical point. Show that the Hessian matrix is only positive semidefinite at this critical point (and the test for a local minimum fails). Show that the critical point is a global minimum of f by rearranging the last three terms to demonstrate that f has a minimum value of zero.
2023-02-06