Exercise
The 2-order approximation of ex(x3 + 1) is
x3 + 1
1 + x + x2/2
1 + x
No, the degree is too high.
Yes.
No, the degree 2 term is nonzero.
Exercise
The 2-order approximation of ex(x3 + 1) is
x3 + 1
1 + x + x2/2
1 + x