QUIZ 3 (IN 10 MINUTES.)
PUID:
NAME:
Newtons law of cooling: The temperature of an object changes at
a rate proportional to the dierence between its termperature and that
of its surroundings.
1. Suppose that the temperature of a cup of coee obeys Newtons l
QUIZ 4 (IN 15 MINUTES.)
NAME:
PUID:
1. Find the integral curve of the following initial value problem,
(9x2 + y 1) (4y x)y = 0, y (1) = 3
(6 points)
2. Classify the stability of the equilibrium solutions of the autonomous
dierential equation
dy
= y (1 y 2
QUIZ 2 (IN 15 MINUTES.)
NAME:
PUID:
1. Solve the equation ty + 2y =
sin t
. (5 points)
t
2. Find the equation of the integral curve passing through (0, 1) for the differential euqation,
dy
4x x3
=
.
dx
4 + y3
(5 points)
Date : January 28th.
1
QUIZ 1 (IN 10 MINUTES.)
NAME:
PUID:
(1) Draw the direction eld of the ordinary dierention equation,
y = 100 0.5y.
What is the equilibrium solution? Determine/describe the behavior of y (t)
as t if y (0) = 120. (7 points)
(2) How many of the following dier