Math Question?

Question

heyy i'm taking the math regents this thursday and I am prepared for the most part.

just one small question:

i was taking a practice regtns and i forgot how to do this problem http://i38.photobucket.com/albums/e104/Superloose16/Picture1.png

(i selected the problem on a screen shot thing) what are these problems called? I want to look them up in my review book.

Answer 1

This is a summation problem, indicated by the capital Greek letter Sigma.  It simply means to add the answers of the equation solved by replacing k with the integers 0 through 3.  So...(3 cos 0*pi +1) + (3 cos 1*pi +1) + (3 cos 2*pi +1) + (3 cos 3*pi +1).

Answer 2

Sigma notation.