### Home > APCALC > Chapter 2 > Lesson 2.1.3 > Problem2-37

2-37.

Calculate the value of the given summation and explain how you found your answer.

• $\displaystyle\sum _ { p = 1 } ^ { 80 } \operatorname { cos } ( \frac { \pi p } { 2 } )$

$\text{Consider the fact that cos}\left ( \frac{\pi p}{s} \right ) \text{ is an even function}.$