# Infinite series. calculus II?

• April 15th 2010, 09:25 PM
andrewt328
Infinite series. calculus II?
Give an example of an infinite series which equals pi/4, which has no term (no multiple) of pi...the series should contain an infinite number of non zero distinct terms

thanks
• April 15th 2010, 09:45 PM
Failure
Quote:

Originally Posted by andrewt328
Give an example of an infinite series which equals pi/4, which has no term (no multiple) of pi...the series should contain an infinite number of non zero distinct terms

thanks

$\sum_{k=1}^\infty \frac{(-1)^{k}}{2k-1}=\arctan(1)=\frac{\pi}{4}$
• April 15th 2010, 09:53 PM
andrewt328
thanks a ton