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.
prove -9cos(3x) - 2(-3(sin(3x)) +3(cos(3x)) = 0
prove -9cos(3x) - 2(-3(sin(3x)) +3(cos(3x)) = 0
Natural Language
Math Input
Extended Keyboard