1. Compute the divergence and curl of each of the following vector fields:
a) hx
2 + y
2
, x2 − y
2
, z2
i
b) hx + y, x − y, zi
2. For any two vector fields F, G show that:
∇.(F × G) = G.(∇ × F) − F.(∇ × G).
3. Given scalar functions u(x, y, z), v(x, y, z), w(x, y, z), φ(x, y, z) and a vector field F(x, y, z) =
hu(x, y, z), v(x, y, z), w(x, y, z)i, prove that
div(φF) = φ(div F) + (∇φ) · F.
4. Find a function f such that F = ∇f where F = hyz, xz, xy + 2zi
5. Let r = hx, y, zi and r = |r|, verify that
a) ∇ · r = 3
b) div (r
n
r) = (n + 3)r
n
6. Given u = xy2
z
2 and v = yz − 3x
2
, find ∇ · [(∇u) × (∇v)]
7. Given the vector field F = he
x
sin y, ex
cos y, zi, show that F is irrotational, hence or
otherwise, find the functions f such that ∇f = F.
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04.01.18, 09:22
6. Find the absolute minimum of f(x, y) = x 2 + y 2 + 2y − 1 on D =
{(x, y)|x 2 + y 2 4 ≤ 1} 7. Use Lagrange multipliers to find the
maximum and minimum values of the function subject to the given
constraint(s). a) f(x, y, z) = xyz; x 2 + 2y 2 + 3z 2 = 6 b) f(x, y,
z) = yz + xy; xy = 1, y2 + z 2 = 1 8. Find the first four terms in the
Taylor series expansion of the function: f(x, y) = e −y 2 cos(x + y)
about the point (0, 0).
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Dear visitor, please use panel for submitting new questions
6. Find the absolute minimum of f(x, y) = x 2 + y 2 + 2y − 1 on D = {(x, y)|x 2 + y 2 4 ≤ 1} 7. Use Lagrange multipliers to find the maximum and minimum values of the function subject to the given constraint(s). a) f(x, y, z) = xyz; x 2 + 2y 2 + 3z 2 = 6 b) f(x, y, z) = yz + xy; xy = 1, y2 + z 2 = 1 8. Find the first four terms in the Taylor series expansion of the function: f(x, y) = e −y 2 cos(x + y) about the point (0, 0).
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