I don't know if it's right that I use calculus to deduce the effective value of sine alternating current I use calculus to deduce the voltage and current RMS of sinusoidal alternating current. I don't know if the process is correct

I don't know if it's right that I use calculus to deduce the effective value of sine alternating current I use calculus to deduce the voltage and current RMS of sinusoidal alternating current. I don't know if the process is correct

Yes, I have. The result is right