Course 4, Week 1, Assignment 2

General question
Why in sequential Api the listing method we need comma , now in
Functional Api we don’t. Just curious .
and in sequential API , we can use the syntax call model. add etc with no comma etc.

In the Sequential API, you fill in an array. In programming, the different values of an array are separated by commas. In the Functional API, you create different lines of code. In Python, there is no semicolon at the end of lines of code.

in sequential model even though we used only 10 epochs we got 95 percent accuracy at last epoch but in functional API even for 100 epoch I got only 80% accuracy at 100th epoch , why is it like this ?
does working of sequential and Functional API affect the model accuracy ?

No. The API makes no difference and both result in exactly the same model being created. It’s just the syntax of the building that differs. See the linked thread for further information.