Chapter 4.5, Problem 9E

9Wire of length 20m is divided into two pieces and the pieces are bent into a square and a circle. How should this be done in order to minimize the sum of their areas? Round your answer to the nearest hundredth.

Use Laplace transform to solve the initial value problem y' + y = tsin(t), y(0) = 0

The function g is defined by g(x) = sec² x + tan x. What are all solutions to g(x) = 1 on the interval 0 ≤ x ≤ 2π ? A x = = 0, x == = 3, x = π, x = 7 4 , 4 and x 2π only = B x = 4' 1, x = 1, x = 57 and x = 3 only C x = πk and x = - +πk D , where is any integer П x = +πk and П x = +πk, where k is any integer

Vector v = PQ has initial point P (2, 14) and terminal point Q (7, 3). Vector v = RS has initial point R (29, 8) and terminal point S (12, 17). Part A: Write u and v in linear form. Show all necessary work. Part B: Write u and v in trigonometric form. Show all necessary work. Part C: Find 7u − 4v. Show all necessary calculations.

An object is suspended by two cables attached at a single point. The force applied on one cable has a magnitude of 125 pounds and acts at an angle of 37°. The force on the other cable is 75 pounds at an angle of 150°.Part A: Write each vector in component form. Show all necessary work.Part B: Find the dot product of the vectors. Show all necessary calculations Part C: Use the dot product to find the angle between the cables. Round the answer to the nearest degree. Show all necessary calculations.

An airplane flies at 500 mph with a direction of 135° relative to the air. The plane experiences a wind that blows 60 mph with a direction of 60°.Part A: Write each of the vectors in linear form. Show all necessary calculations.Part B: Find the sum of the vectors. Show all necessary calculations. Part C: Find the true speed and direction of the airplane. Round the speed to the thousandths place and the direction to the nearest degree. Show all necessary calculations.

Use sigma notation to write the sum. Σ EM i=1 - n 2 4n + n n

Vectors t = 3i + 7j, u = 2i − 5j, and v = −21i + 9j are given.Part A: Find the angle between vectors t and u. Show all necessary calculations. Part B: Choose a value for c, such that c > 1. Find w = cv. Show all necessary work.Part C: Use the dot product to determine if t and w are parallel, orthogonal, or neither. Justify your answer.

A small company of science writers found that its rate of profit (in thousands of dollars) after t years of operation is given by P'(t) = (5t + 15) (t² + 6t+9) ³. (a) Find the total profit in the first three years. (b) Find the profit in the sixth year of operation. (c) What is happening to the annual profit over the long run? (a) The total profit in the first three years is $ (Round to the nearest dollar as needed.)