MathDB
Problems
Contests
Undergraduate contests
Putnam
1981 Putnam
A3
A3
Part of
1981 Putnam
Problems
(1)
Putnam 1981 A3
Source: Putnam 1981
3/31/2022
Find
lim
t
→
∞
e
−
t
∫
0
t
∫
0
t
e
x
−
e
y
x
−
y
d
x
d
y
,
\lim_{t\to \infty} e^{-t} \int_{0}^{t} \int_{0}^{t} \frac{e^x -e^y }{x-y} \,dx\,dy,
t
→
∞
lim
e
−
t
∫
0
t
∫
0
t
x
−
y
e
x
−
e
y
d
x
d
y
,
or show that the limit does not exist.
Putnam
limit
Double integral