I have to match each polynomial formula with the correct Maclaurin polynomial below. I am confused as to how to do this, so any help would be appreciated.

a) f(x) = (e^-x)-1

b) f(x) = 1/(x+1)

c) f(x) = 1/(1-x)

d) f(x) = (e^x) + sin(x)

1) 1 + x + x^2 + x^3

2) 1 + 2x + (X^2)/(2)

3) -x + (x^2)/(2) - (x^3)/(3)

4) 1 - x + x^2 - x^3