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Home Quiz 2, MATH 251, Section 506
Due April 7th 2016
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”An Aggie does not lie, cheat or steal, or tolerate those who do”
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Write up your result, detail your calculations if necessary and BOX your final answer.
Your final work have to be neat, so use pencil first if you want.
Z
1. [8pts] Evaluate the integral by reversing the order of integration
0
8Z 2
1
y3
p
x4 + 1 dx dy.
2. [15pts] Find the volume of the solid E in the first octant bounded by the paraboloid z = 12 (x2 + y 2 )
p
and the cone z = 2x2 + 2y 2 and coordinate planes.
Z Z
3. [10pts] Evaluate
yxdA, where D is the triangular region with vertices (0, 0), (2, 1), (2, 2) and
D
sketch also the domain D.
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4. [8pts] Find the volume of the solid E bounded by the paraboloid z = 2 − x2 − y 2 and the paraboloid
z = 1 + x2 + y 2 .
5. [8pts] Find the total mass of the lamina having the density ρ(x, y) = xy and occupying the region D
which is in the first quadrant bounded by y = x2 and y = 1.
6. [15pts] Find the area enclosed by the ellipse
x2 y 2
+
= 1 (Hint : Use Green’s Theorem).
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7. Let the tetrahedron be bounded by the coordinates planes and the plane 2x + 2y + z = 2 with density
ρ(x, y, z) = y .
(a) [8pts] Find the mass of this tetrahedron.
(b) [8pts] Find the y-coordinate ȳ of the center of mass of this tetrahedron.
Z
8. Consider the line integral
F.dr where F is the vector field F =< 4x2 − 6y, 4x + y 2 > and C is the
C
positively oriented circle of radius 3 centered at the origin. Evaluate the integral (Show your work)
(a) [10pts] Directly
(b) [10pts] By Green’s Theorem
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