Use the theorems of this section to find f1 for the following:
a. f(x, y, z) = xy
b. f(x, y) = sin (xsin (y)).
c. f(x, y, z) = sin (xsin (ysin (z))
d. f(x, y, z) = xy2
e. f(x, y, z) =xy+z
f. f(x, y, z) =(x + y)z
g. f(x, y) = sin (xy)
h. f(x, y) = sin (xy) cos(3)
i. f(x, y) =(sin(xy), sin (xsin (y)),xy)