Answer:
For a function f(x,y) in two variables we have
[tex]df=\frac{\partial f}{\partial x}dx+\frac{\partial f}{\partial y}dy[/tex]
We have
[tex]f(x,y)=2x+3y-xy\\\\\therefore \frac{\partial f}{\partial x}=2-y\\\\\frac{\partial f}{\partial y}=3-x\\\\[/tex]
[tex]df=(2-y)dx+(3-x)dy\\\\\Delta f=(2-y)\Delta x+(3-x)\Delta y[/tex]
Applying values we get
[tex]df=(2-y)dx+(3-x)dy\\\\\Delta f=(2-1)(3-2.95)+(3-3)(1-1.04)\\\\\Delta f=0.05[/tex]
