ODE 602S
Ordinary Differential Equations
January 2023
1. Solve the following initial value problems:
(a)
x2y'(x) 3
+xy(x)=
5
e-x
5
,
y(-1)=0,
for x<0
(5)
(b)
y'(x) sinx + y(x) cosx = 2ex, y(l) = a, 0 < x < 1r
(5)
(c) If a constant number k of fish are harvested from a fishery per unit time, then a
logistic model for the population P(t) of the fishery at time t is given by
d:?) = P(t)(5 - P(t)) - 4, P(0) = Po
i. Solve the IVP.
(5)
11. Determine the time when the fishery population becomes quarter of the initial
population
(5)
2. (a) If y1 and y2 are two solutions of second order homogeneous differential equation of
the form
y"(x) + p(x)y'(x) + q(x)y(x) = f(x)
where p(x) and q(x) are continuous on an open interval I, derive the formula for
u(x) and v(x) by using variation of parameters.
(6)
(b) If
find Y2(x)
(7)
(c) Solve
8x2y"(x) + 16xy'(x) + 2y(x) = 0
(7)
3. (a) Solve the Euler equation
x 2y"(x) + 15xy'(x) + 58y(x) = 0, y(l) = 1, y'(l) = 0
(7)
(b) Solve the following differential equations by method of variation of parameters
y"(x) + y(x) = tanx
(8)
(c) Solve the following differential equations by method of undetermined coefficients
y"(x) + 2y'(x) + 2y(x) = -ex(5x - 11), y(0) = -1, y'(0) = -3
(5)