Math 234 - Final Exam - Spring 2022
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Math 234 - Final Exam - Spring 2022
1. (12 points) Use Lagrange multipliers to find the maximum and minimum values of f(x,y) = xy subject to the constraint 4x2 + y2 = 8.
2. (12 points) Use Green’s Theorem to evaluate the line integral along the given positively
oriented curve
ZC 2x2y2 dx +3x3ydy
where C is the triangle with vertices (0, 0), (0, 2) and (2, 2).
3. (12 points) Let C be the line segment from (0, 0) to (3, 4).
(a) (6 points) Evaluate
ZC 3x + y ds.
(b) (6 points) Let F(x,y) = hy2 ,y − 2xi. Evaluate
ZC F · dr.
4. (12 points) Let
(x,y,z) = h2x + z3 e3y2 ,y +ln(4x2 +5), 3z + x2 i.
(a) (3 points) Compute the divergence of the vector field .
(b) (9 points) Use the Divergence Theorem to compute ZZS · dS~ outward through the
sphere S of radius 1 centered at the origin.
5. Consider the triple integral
Z 1 Z^1−x2 Zy
(a) (3 points) Let E be the region of integration for the above integral. Fill in the blanks of
the following sentence: “The region E is inside the cylinder *blank* and bounded below by the plane *blank* and above by the plane *blank*.”
(b) (4 points) Express dV as an iterated triple integral in Cartesian coordinates with
(c) (4 points) Express dV in cylindrical coordinates.
E
(d) (3 points) Compute dV using any method.
E
6. (12 points) Let S be the surface described by z = ^x2 + y2 that lies between the planes z = 1 and z = 5.
(a) (3 points) Let D be the region in the uv-plane so that
r~(u,v) = hucos(v),usin(v),ui with (u,v) in D
parametrizes S . Sketch D . Shade the region(s) that are part of D . Use dotted lines when sketching a curve that is NOT in D, and solid lines when sketching curves that are.
(b) (6 points) Compute r~u ⇥ r~v .
(c) (3 points) Compute the surface area of S .
7. (12 points) Consider the vector field (x,y) = hyex ,ex + ey i.
(a) (3 points) Show that is conservative.
(b) (5 points) Find a function f such that rf = .
(c) (4 points) Evaluate the integral ZC yex dx +(ex + ey )dy, where C is any path from (1, 2) to (3, 0).
8. (14 points) Let C1 be the curve parameterized by r~1 (t) = h2,t +1,t2 − 2t +4i and let C2 be the curve parametrized by r~2 (t) = ht2 +2,t3 +2t +3, 4t +4i.
(a) (5 points) The curves C1 and C2 intersect at a single point Q. Find Q.
(b) (5 points) Find parametric equations for the tangent lines of C1 and C2 at Q.
(c) (4 points) Are the tangent lines the same? Why or why not?
2022-12-28