Science:Math Exam Resources/Courses/MATH200/December 2012/Question 03 (b)/Statement

Suppose that a function $z=f(x,y)$ is implicitly defined by an equation: $xyz+x+y^2+z^3=0$

(b) If $f(-1,1)<0$, find the linear approximation of the function $z=f(x,y)$ at $(-1,1)$.