Multi-Variable Calculus Assignment

due Tuesday, May 1, 2001

The Fundamental Theorem of Multi-Variable Calculus

Each of the following three statements is a form of the fundamental theorem of calculus. Functions involved are generally assumed to be differentiable.

A. If C is a parameterized path from the point A to the point B in n-space and f is a scalar-valued function of n variables, then

 INT[_{C}  \nabla f ]   =    f(B) - f(A) .  

B. If S is a piece of parameterized surface in 3-space with (parameterized) boundary \partial S and F is a vector-field in 3-space that is well-behaved near S, then

 INT[INT[_{S}  curl F ]]   =     INT[_{\partial S}  F ].  

C. If D is a solid domain in 3-space with boundary surface \partial D, oriented by its normal pointing outside D, and F is a vector-field in 3-space that is well-behaved in and around D, then

 INT[INT[INT[_{D} div F ]]]   =     INT[INT[_{\partial D}  F ]].  

Exercises

  1. Let F be the vector field in space that is given by

     F(x, y, z)    =    (yz, zx, xy) .  
    Apply statement (A) above to evaluate the integral of F over
    1. the line segment from the origin to the point (1, 2, 3).

    2. either semi-circle in the plane x + y - z = 0 traversed from the origin to the point (1, 2, 3).

  2. Let F(x, y, z) = (x + y^{2}, y + z^{3}, z + x^{4}). Apply statement (C) above to evaluate the integral of F over the sphere of radius a > 0 with center at the origin when the sphere is parameterized, as usual, using ``longitude'' as first parameter and ``co-latitude'' as second parameter.

  3. Let F be the vector field in space that is given by

     F(x, y, z)    =    (y + 2 z, z + 2 x, x + 2 y) .  
    Compute
     INT[INT[_{S}  curl F ]] 
    when S is the upper-half of the sphere x^{2} + y^{2} + z^{2} = 25 parameterized using ``longitude'' and ``co-latitude'', as above.

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