So I am trying to double check some work that I did, basically it involves solving a frequency property relationhip for stiffness here is the Base equation 

F(natural frequency)= (a/2Pi)sqrt((EIg/WL^4)) where a is a constant w is weight/unit legnth L is the legnth, E is the stiffness (youngs mod) I is the moment of inertia and g is acceleration due to gravity in in/sec^2

the problem is, when I input that equation into Wolfram alpha it gets "confused by E and I" obviously, so I substituted them for other varibles, the real problem comes with that third varible is the numerator under the sqaure root. after that it comes back with 

"Using closest Wolfram|Alpha interpretation: F=(a/2Pi)" 

it had no problem understanding F=(a/2Pi) before. Any ideas ?