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.
-13*sin x +10*sin(2x) +6*sin (3x) + 4*sin(4x) =0
Natural Language
Math Input
Extended Keyboard
Examples
Upload
Random