Find the Terms in the Maclaurin Series for the Function $f ( x ) = e ^ { - x }$

Multiple Choice

Find the terms in the Maclaurin series for the function $f ( x ) = e ^ { - x }$ , as far as the term in $x ^ { 3 }$ .

A) $1 - x + \frac { 1 } { 2 } x ^ { 2 } - \frac { 1 } { 6 } x ^ { 3 }$
B) $1 + x + \frac { 1 } { 2 } x ^ { 2 } - \frac { 1 } { 6 } x ^ { 3 }$
C) $1 - x + x ^ { 2 } - x ^ { 3 }$
D) $1 + x + x ^ { 2 } + x ^ { 3 }$
E) $1 - x + \frac { 1 } { 2 } x ^ { 2 } - \frac { 1 } { 3 } x ^ { 3 }$
F) $1 + x + \frac { 1 } { 2 } x ^ { 2 } + \frac { 1 } { 3 } x ^ { 3 }$
G) $- x + x ^ { 3 }$
H) $x - x ^ { 3 }$