Consider the following three functions:
g(x, y) = 4x - 9y2
h(x, y, z) = 13x + y + 3z -6
i(y, z) = z - y
Which of the following is true regarding the linearity of the functions?
a) none of the functions is linear
b) all three functions are linear
c) h is linear, but g and i are not linear
d) i is linear, but g and h are not linear
e) h and i are linear, but g is not linear
Answer: e