To calculate the theoretical discharge, it seems like you are working with formulas related to fluid mechanics, likely involving the discharge equation or some relevant hydraulic calculations.

The image shows some partial values and symbols, but it's unclear due to the handwriting. Could you please provide some of the numerical values or formulas you're working with? Alternatively, if this is related to a specific scenario (e.g., a flow in a pipe, orifice, or channel), let me know and I can guide you with a more detailed explanation of the theoretical discharge equation relevant to your case.