ABSTRACT
Functions of several variables are usually visualized through their 3D graph. Another method is through the use of level curves of the function using equations such as f(x 1 , x 2) = k. Consider the function f ( x , y ) = 9 − x 2 − y 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003009573/94296aab-a863-4b69-a9f7-e057ead7b3b0/content/C005_equ_0001.tif"/>
