Show all work. 1. Find two nonnegative real numbers x and y such that x + y = 24 and x2 + y2 is maximized and show why it is a maximum using calculus. 3. The length of a rectangle is decreasing at a rate of 2 cm/sec, while the width wis increasing at the rate of 3 cm/sec. At the moment when the length / is 12 cm and the width wis 5 cm, find the rate at which...
Let x represent one number and let y represent the other number. Twice a first number decreased by a second number is 5. The first number increased by four times the second number is - 29. Use the given conditions to write a system of equations. Solve the system and find the numbers. Write a system of equations. ОА. B 3x +y = - 30 ( x + y = - 30 |2x - y = 5 x + 4y...
Let the domain for x and y be R, the set of real numbers. (a) Determine the truth value of ∀x∃y (y = √ x). Explain (b) Determine the truth value of ∃y∀x (y = √ x). Explain
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...
x+3 2x Define f(x) for all real numbers x = 0. Is f a one-to-one function? Prove or give a counterexample. (Note that the write-up of the proof or counterexample should only have a few of sentences.) If the co-domain is all real numbers not equal to 1, is f an onto function? Why or why not? (Note this problem does not require a full proof or formal counterexample, just an explanation.)
4. Let f(x) = 6-2x, 0<x 2 (a) Expand f(x) into a periodic function of period 2, ie. construct the function F(x), such that F(x)-f (x), 0xS 2, and Fx) F(x+2) for all real numbers x. (This process is called the "full-range expansion" of f(x) into a Fourier series.) Find the Fourier series of Fr). Then sketch 3 periods of Fx). (b) Expand fx) into a cosine series of period 4. Find the Fourier series and sketch 3 periods (c)...
14. Find two positive real numbers with a maximum product whose sum is 110. Write one number in each blank. 15. Find two positive real numbers where the sum of the first number and twice the second is 36. Find the two numbers that maximize the product. Write one number in each blank. 16. A rectangular garden is planted right up next to the wall of a building, and it going to have edging on three sides. If 54 feet...
V01 (version 953): Let V be the set of all pairs (x,y) of real numbers together with the following operations: (x1, yı) © (C2, y2) = (x1 + 22,41 + y2) cº (x, y) = (Acc, 4cg). (a) Show that scalar multiplication distributes over scalar addition, that is: (c+d) 9 (z, 3) = c+ (x, y) #de (x, y). (b) Explain why V nonetheless is not a vector space.
3Y 2 1. (20 points) Suppose that X and Y independent random variables. Let W 2x (a) Consider the following probability distribution of a discrete random variable X: 12 P(X) 00.7 0.3 X Compute the mean and variance of X (b) Use your answers in part (a). If E(Y)=-3 and V(Y)= 1, what are E(W) and V (W)?
Prove that for any two real numbers x and y, |x + y| ≤ |x| + |y|. Hint: Use the previously proven facts that for any real number a, |a|≥ a and |a|≥−a. You should need only two cases.