ap-calculus-bc 2012 Q17

ap-calculus-bc · Usa · practice-exam Taylor series Identify a closed-form function from its Taylor series
For $x > 0$, the power series $1 - \frac { x ^ { 2 } } { 3 ! } + \frac { x ^ { 4 } } { 5 ! } - \frac { x ^ { 6 } } { 7 ! } + \cdots + ( - 1 ) ^ { n } \frac { x ^ { 2 n } } { ( 2 n + 1 ) ! } + \cdots$ converges to which of the following?
(A) $\cos x$
(B) $\sin x$
(C) $\frac { \sin x } { x }$
(D) $e ^ { x } - e ^ { x ^ { 2 } }$
(E) $1 + e ^ { x } - e ^ { x ^ { 2 } }$
For $x > 0$, the power series $1 - \frac { x ^ { 2 } } { 3 ! } + \frac { x ^ { 4 } } { 5 ! } - \frac { x ^ { 6 } } { 7 ! } + \cdots + ( - 1 ) ^ { n } \frac { x ^ { 2 n } } { ( 2 n + 1 ) ! } + \cdots$ converges to which of the following?

(A) $\cos x$

(B) $\sin x$

(C) $\frac { \sin x } { x }$

(D) $e ^ { x } - e ^ { x ^ { 2 } }$

(E) $1 + e ^ { x } - e ^ { x ^ { 2 } }$