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.
s
o
l
v
e
f
o
r
L
2
π
f
L
1
=
1
2
π
f
C
Math Input
Natural Language
Math Input
