(FMU - FIAM) O valor de $\,\operatorname{sen}x \,+\,{\large \frac{\operatorname{sen}^3 x}{2}} \,+ \, {\large \frac{\operatorname{sen}^5 x}{4}} \,+\,...\;$ é:
a)
$\,\dfrac{\operatorname{sen}x}{1\,+\,\operatorname{sen^2}x}\,$
b)
$\,\dfrac{\operatorname{cos}x}{1\,-\,\operatorname{sen^2}x}\,$
c)
$\,\dfrac{\operatorname{sen}x}{1\,+\,\operatorname{cos^2}x}\,$
d)
$\,\dfrac{\operatorname{sen}x}{1\,-\,\operatorname{sen^2}x}\,$
e)
$\,\dfrac{2\operatorname{sen}x}{1\,+\,\operatorname{cos^2}x}\,$
