Uh oh! Wolfram|Alpha doesn't run without JavaScript.
Please enable JavaScript. If you don't know how, you can find instructions
here
.
Once you've done that, refresh this page to start using Wolfram|Alpha.
sum ( 1/(cos(k*pi/180)*cos((k+1)*pi/180)) , k=0 to 44
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random