Calculus II Quiz 2 Apr. 9, 2009
Name: Student ID number:
1. (10 pts) Compute the Taylor polynomial of degree 2 about a = 0 for f (x) = 1
1 + x.
2. (10 pts) Solve dy
dx = 3y, with y(0) =−5, i.e. y = −5 when x = 0.
3. Suppose that dy
dx = y(y− 1)
(a) (10 pts) Find the equilibria of the differential equation.
(b) (10 pts) Discuss the stability of the equilibria (by graph or eigenvalue)
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Name: Student ID number:
4. Given a matrix A =
[ 4 2
−3 −1 ]
(a) (20 pts) Find the eigenvalues and eigenvectors of A
(b) (10 pts) Let v1, v2 be two eigenvectors found in part (4a). Find A10v1 and A10v2 without using a calculator.
5. (10 pts) Show that lim
(x,y)→(0,0)
2xy
x2+ y2 does not exist.
6. (20 pts) Given f (x) = 2x− 1
xy, find ∂f
∂x and ∂f
∂y.
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