ECON 255 - Winter 2023 - Assignment 4
Hello, dear friend, you can consult us at any time if you have any questions, add WeChat: daixieit
ECON 255 - Winter 2023 - Assignment 4
Due by March 4th on course website
Question 1
1. Let f (x, y) = (x2 − 3y)(x − 2). Find fy (1, 2).
2. Let f (x, y) = . Find fx (1, 2)
Question 2
1. Find the differential dy at x = 2 of f (x) = x5 , when dx = 0.005. (Please write answer as number with 2 decimal places)
2. Deduce an estimate of 2.0055 by linear approximation. (Please write answer as number with 2 decimal places)
Question 3
Let z = and x =
Find evaluated at y = 1.
Question 4
Let f (x, y, w) = x2 + y3 + w4 . Find the determinant |H0 | of the Hessian matrix for this function, when evaluated at x0 =(5, 1, ).
Question 5
Given z = x2 − 8xy − y3 where x = 3t and y = 1 − t, find the total derivative at t = −1.
Question 6
Let X = xy + y2 .
Calculate |dX − ∆X | at dx = dy = 0.1. This is the (absolute value of the) error that one commits if dX is used instead of ∆X . (Please write answer as number with 2 decimal places)
2023-03-06