Ł
1
2
1
(4p)
dx
x ln x
0

(5p)
D = (x, y, z) " R3 : (x2 + y2 + z2)2(x2 + y2) d" 1
(4p)
ł(t) = (cos t, sin t, at) 0 d" t d" 2Ą a " R
F (x, y) =
(7p)
x + 2y 2x2 + y2 + xy = 1
x2y
f(x, y) = (x, y) = (0, 0) f(0, 0) = 0

x2+y2
"f "f
(6p)
(0, 0) (0, 0) f (0, 0)
"x "y

(2y dx + 3x dy)
�
(4p)
� (0, 0) 1
Ą
x cos y = y cos x x = y = f(x)
2
(6p)
f(Ą ) = -Ą f (0)
2 2
(4p)
f (t) - f (t) + f (t) - f(t) = 0