1. Find the linear approximation to the function

f(x,y) =(12+2xy)(1/2) at the point (x,y)=(2,2)(x,y)=(2,2)

and Use this linear approximation to estimate f(1.99,2.01)

2. The tangent plane to the surface with equation

z=xln(y)+x2y+4at the point (x,y,z)=(3,1,13)(x,y,z)=(3,1,13)

3. The tangent plane to the surface with equation

f(x,y)=(ex+y)32xy+1at the point (x,y)=(0,2)