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Vectors and calculus, lots of help needed (very urgent)
Let S be part of the cylinder x2+z2=1 that lies above the rectangle in the plane z=0 that has vertices (1/2,1/2,0),(1/2,-1/2,0),(-1/2,-1/2,0) and (-1/2,1/2,0). By evaluating ∫∫S 1 ds, find the surface area of S.
For the cylinder x=cosθ ,z=sinθ
r(θ,y)=cosθi+yj+sinθk
0≤θ≤2π and -1/2≤y≤1/2
rθ = -sinθi+cosθk
ry=j
rθxry=-sinθk-cosθj
|rθxry|=1
∫∫S 1 ds = ∫∫|rθxry| dA
[tex]\int_0 ^{2\pi} \int_{\frac{-1}{2}} ^{\frac{1}{2}} y dy d\theta[/tex]
is this correct? (I am not getting the correct answer)
Evaluate the surface integral ∫∫S (y2i+x2j+z4k).n ds
where S is the part of the cone defined by [itex]z=4 \sqrt{x^2+y^2}, 0 \leq z \leq8 \and \ y \geq 0[/itex]. Assume S has an upward orientation.
I know I need to find out what is n but I don't know what to parameterize to find n.
Let E be the solid region enclosed by the paraboloid z=1-x2-y2 and the plane z=0. Evaluate the surface integral
∫∫(yi+xj+zk).n ds
Where S is the boundary surface of E that has outward orientation.
Evaluate
Let S be part of the cylinder x2+z2=1 that lies above the rectangle in the plane z=0 that has vertices (1/2,1/2,0),(1/2,-1/2,0),(-1/2,-1/2,0) and (-1/2,1/2,0). By evaluating ∫∫S 1 ds, find the surface area of S.
For the cylinder x=cosθ ,z=sinθ
r(θ,y)=cosθi+yj+sinθk
0≤θ≤2π and -1/2≤y≤1/2
rθ = -sinθi+cosθk
ry=j
rθxry=-sinθk-cosθj
|rθxry|=1
∫∫S 1 ds = ∫∫|rθxry| dA
[tex]\int_0 ^{2\pi} \int_{\frac{-1}{2}} ^{\frac{1}{2}} y dy d\theta[/tex]
is this correct? (I am not getting the correct answer)
Evaluate the surface integral ∫∫S (y2i+x2j+z4k).n ds
where S is the part of the cone defined by [itex]z=4 \sqrt{x^2+y^2}, 0 \leq z \leq8 \and \ y \geq 0[/itex]. Assume S has an upward orientation.
I know I need to find out what is n but I don't know what to parameterize to find n.
Let E be the solid region enclosed by the paraboloid z=1-x2-y2 and the plane z=0. Evaluate the surface integral
∫∫(yi+xj+zk).n ds
Where S is the boundary surface of E that has outward orientation.
Evaluate ∫∫∫E 1/2 (x2+y2)2 dV
Where E= {(x,y,z)|x2+y2≤4,-2≤z≤2}
I tried to convert to cylindrical coordinates and got this
0≤r≤2 0≤θ≤2π and -2≤z≤2
[tex]\int \int \int \frac{1}{2}(x^2+y^2)^2 dV = \int_0 ^{2\pi} \int_0 ^2 \int_2 ^2 \frac{1}{2} \times 16 rdzdrd\theta[/tex]
Once again, I get the wrong answer. Please help me.
Homework Statement
Let S be part of the cylinder x2+z2=1 that lies above the rectangle in the plane z=0 that has vertices (1/2,1/2,0),(1/2,-1/2,0),(-1/2,-1/2,0) and (-1/2,1/2,0). By evaluating ∫∫S 1 ds, find the surface area of S.
The Attempt at a Solution
For the cylinder x=cosθ ,z=sinθ
r(θ,y)=cosθi+yj+sinθk
0≤θ≤2π and -1/2≤y≤1/2
rθ = -sinθi+cosθk
ry=j
rθxry=-sinθk-cosθj
|rθxry|=1
∫∫S 1 ds = ∫∫|rθxry| dA
[tex]\int_0 ^{2\pi} \int_{\frac{-1}{2}} ^{\frac{1}{2}} y dy d\theta[/tex]
is this correct? (I am not getting the correct answer)
Homework Statement
Evaluate the surface integral ∫∫S (y2i+x2j+z4k).n ds
where S is the part of the cone defined by [itex]z=4 \sqrt{x^2+y^2}, 0 \leq z \leq8 \and \ y \geq 0[/itex]. Assume S has an upward orientation.
The Attempt at a Solution
I know I need to find out what is n but I don't know what to parameterize to find n.
Homework Statement
Let E be the solid region enclosed by the paraboloid z=1-x2-y2 and the plane z=0. Evaluate the surface integral
∫∫(yi+xj+zk).n ds
Where S is the boundary surface of E that has outward orientation.
The Attempt at a Solution
Evaluate
Homework Statement
Let S be part of the cylinder x2+z2=1 that lies above the rectangle in the plane z=0 that has vertices (1/2,1/2,0),(1/2,-1/2,0),(-1/2,-1/2,0) and (-1/2,1/2,0). By evaluating ∫∫S 1 ds, find the surface area of S.
The Attempt at a Solution
For the cylinder x=cosθ ,z=sinθ
r(θ,y)=cosθi+yj+sinθk
0≤θ≤2π and -1/2≤y≤1/2
rθ = -sinθi+cosθk
ry=j
rθxry=-sinθk-cosθj
|rθxry|=1
∫∫S 1 ds = ∫∫|rθxry| dA
[tex]\int_0 ^{2\pi} \int_{\frac{-1}{2}} ^{\frac{1}{2}} y dy d\theta[/tex]
is this correct? (I am not getting the correct answer)
Homework Statement
Evaluate the surface integral ∫∫S (y2i+x2j+z4k).n ds
where S is the part of the cone defined by [itex]z=4 \sqrt{x^2+y^2}, 0 \leq z \leq8 \and \ y \geq 0[/itex]. Assume S has an upward orientation.
The Attempt at a Solution
I know I need to find out what is n but I don't know what to parameterize to find n.
Homework Statement
Let E be the solid region enclosed by the paraboloid z=1-x2-y2 and the plane z=0. Evaluate the surface integral
∫∫(yi+xj+zk).n ds
Where S is the boundary surface of E that has outward orientation.
The Attempt at a Solution
Homework Statement
Evaluate ∫∫∫E 1/2 (x2+y2)2 dV
Where E= {(x,y,z)|x2+y2≤4,-2≤z≤2}
Homework Equations
The Attempt at a Solution
I tried to convert to cylindrical coordinates and got this
0≤r≤2 0≤θ≤2π and -2≤z≤2
[tex]\int \int \int \frac{1}{2}(x^2+y^2)^2 dV = \int_0 ^{2\pi} \int_0 ^2 \int_2 ^2 \frac{1}{2} \times 16 rdzdrd\theta[/tex]
Once again, I get the wrong answer. Please help me.