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.
Integrate[10 Cos[k x], {x, 0, Pi/2}] + Integrate[-5 Cos[k x], {x, Pi/2, 3Pi/2}]
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random