Let A = ∂ 2w/∂x2 , B = ∂ 2w/∂x∂y, C = ∂ 2w/∂y2 . From the calculus of functions of two variables, w(x, y), we have a saddle point if B 2 − AC > 0. With f (z) = u(x, y) + iv(x, y), apply the Cauchy–Riemann conditions and show that neither u(x, y) nor v(x, y) has a maximum or a minimum in a finite region of the complex plane. (See also Section 7.3.)


2. Let R be the region R = {(X,Y)|X2 + y2 < 2} and let (X,Y) be a pair of random variables that is distributed uniformly on this region. That is fx,y(x, y) is constant in this region and 0 elsewhere. State the sample space and find the probability that the random variable x2 + y2 is less than 1, P[X2 +Y? < 1].
Cal 4
, ) and use this to 6. Let f(x,y) = x2 + y2 + 2x + y. (a) Find all critical points of f in the disk {(x,y) : x2 + y2 < 4). Use the second derivative test to determine if these points correspond to a local maximum, local minimum, or saddle point. (b) Use Lagrange multipliers to find the absolute maximum/minimum values of f(x, y) on the circle a2 +y -4, as well as the points...
Exercise 11. Let Xi,y, be random variables with joint PDF fXiXi. Let X2,Y2 be random variables with joint PDF fx2,Y2. Let T: R2R2 and let S: R2 -R2 so that ST(x, y) (z, y) and TS(a, y) (x, y) for every (x, y) E R2. Let J(x, y) denote the determinant of the Jacobian of S at (x,y. Using the change of variables formula from multivariable calculus, show that
Let f(x, y) = x2 – yż and D= {(2,y) : x2 + y2 < 4}. Let m and M be the absolute minimum and maximum values of f over D respectively. What is m - M?
Problem 1 You are given the maximum and minimum of the function f(x, y, z) = x2 - y2 on the surface x2 + 2y2 + 3z2 = 1 exist. Use Lagrange multiplier method to find them. Let us recall the extreme value theorem we discussed before the spring break: Extreme Value Theorem (For Functions Of Two Variables) If f(x,y) is continuous on a closed, bounded region D in the plane, then f attains a maximum value f(x,y) and a...
6 (20 pts). Let F(x, y, z) = x2 + y2 + x2 - 6xyz. (1) Find the gradient vector of F(x, y, z); (2) Find the tangent plane of the level surface F(x, y, z) = x2 + y2 + x2 - 6xyz = 4 at (0, 0, 2); (3) The level surface F(x, y, z) = 4 defines a function z = f(x,y). Use linear approxi- mation to approximate z = = f(-0.002,0.003).
circle x2 + y2-9 in the x-y plane, oriented counter-clockwise. Let F(x, y, z)-(y,-x,0) Verify Stokes' Theorem by calculating a) surl(F) nds and b) F Tds.
circle x2 + y2-9 in the x-y plane, oriented counter-clockwise. Let F(x, y, z)-(y,-x,0) Verify Stokes' Theorem by calculating a) surl(F) nds and b) F Tds.
1. Find the absolute maximum and minimum values of f(r,y) = x2+y2+5y on the disc {(x, y) | x2+y2 < 4}, and identify the points where these values are attained 2. Find the absolute maximum and minimum values of f(x, y) = x3 - 3x - y* + 12y on the closed region bounded by the quadrilateral with vertices at (0,0), (2,2), (2,3), (0,3), and identify the points where these values are attained. 3. A rectangular box is to have...
All of 10 questions, please.
1. Find and classify all the critical points of the function. f(x,y) - x2(y - 2) - y2 » 2. Evaluate the integral. 3. Determine the volume of the solid that is inside the cylinder x2 + y2- 16 below z-2x2 + 2y2 and above the xy - plane. 4. Determine the surface area of the portion of 2x + 3y + 6z - 9 that is in the 1st octant. » 5. Evaluate JSxz...
solve number 3
2. Show that u(x, y) = e = cos 12 + y2 is harmonic on the punctured complex plane D=C\{0}, and find a harmonic conjugate v of it. 1 2 3. Reveal, what is f(x) = u(x,y) + iv(I,y) in Problem 2?