Suppose That $\operatorname { grad } f ( 1 , - 1 ) = \vec { v }$

question 67

Short Answer

Suppose that $\operatorname { grad } f ( 1 , - 1 ) = \vec { v }$ , with $\| \vec { v } \| = 4$ (a)What is the directional derivative of f at (1, -1)in the direction of $3 \vec { v }$ ?
(b)What is the smallest value of the directional derivative of f at (1, -1)among all possible directions?

---

Definitions:

Disposable Income

Financial endowment to households for the purpose of spending and saving after mandatory tax deductions.

Consumption

The use of goods and services by households. It represents the end-use of products and is a primary component of aggregate demand in an economy.

Disposable Income

The allocation of funds households have to spend and save, after income tax adjustments.

Wage Earning

The act of receiving regular compensation for labor or services, typically on an hourly, daily, or piecework basis.