Undefined variable

[CamilleLaflamme]

Hi, I asked to solved C3 in a simple equation and then it tels me that C3 is undefined. I do not understand, because I did defined C3 with my equality where I find it's value.

Thank you 

 

[VipulT · Accepted solution]

@CamilleLaflamme

You can use symbolic evaluation 

[CamilleLaflamme]

Works juste fine thank's a lot !! 

[Werner_E]

In Prime we have numerical (=) and symbolic (->) evaluation. Numerical evaluation requires that all used variables have to be defined with numerical values so it can yield a numeric result.

Your definition of C3 uses the undefined variables E and I and thats the reason for the error message.