MATLAB mistaken Inertia I for imaginary number what do i do?

[GreenPrint]

MATLAB tends to mistake I or i for imaginary number when ever I try to use it as a variable, for example when do with a pendulum with a mass attached to it then

2 pi f = sqrt( (m g L)/I )
were I is the inertia not imaginary number
but when I try to get MATLAB to solve this equation for L it returns it as a lower case i because it thinks it's the imaginary number
How do I get around this
example

disp('If a pendulum on Earth has a mass of 10 kg, a frequency of .2 Hz, and a inertia of 60 kg m/s,')
fprintf('then it''s legnth is %s m.\n',char(solve(subs('2*pi*f=((m*g*L)/I)^(1/2)',{'f' 'g' 'I' 'm'},{.2 9.8 60 10}),'L')))
If a pendulum on Earth has a mass of 10 kg, a frequency of .2 Hz, and a inertia of 60 kg m/s,
then it's legnth is (2*pi^2*sqrt(-1))/1225 m.

As you can see... This was suppose to solve the equation for L and then plug in the values and return the exact answer instead it returns sqrt(-1) because it mistook I for the imaginary number

 

[uart]

Normally MATLAB has no problems overriding the predefined constant of I=sqrt(-1). I usually prefer to just use another variable name, but in the past I've used I (and i) as a variable without any issue.

Try assigning the variables with there numerical values before calling solve. As in,

f = 0.2
g = 9.8
I = 60
etcEdit. Ok I just realized you're using the symbolic solver and I'm not so sure how it works in this regard. Maybe you'll need to use an alternate symbol for moment of inertia.