Summary: Math 213-001 201130
Assignment # 3 - Sample Answers
1. Let f(x, y) = ln(x + y - 1).
(a) Evaluate f(1, 1).
(b) Evaluate f(e, 1).
(c) Find the domain of f.
Answer.
(a) f(1, 1) = ln(1 + 1 - 1) = ln(1) = 0.
(b) f(e, 1) = ln(e + 1 - 1) = ln(e) = 1.
(c) For f to make sense, we need x + y - 1 > 0.
-4 -2 2 4
-4
-2
2
4
6
Figure 1: The domain consists of those points above the line
2. Find and sketch the domain of the function f(x, y) =

1 + x - y2.

Source: Argerami, Martin - Department of Mathematics and Statistics, University of Regina

Collections: Mathematics