DLS Course 2 Week 1 Exercise 3 - gradient_check

please help me to resolve this problem

thank you

The difference should be small, and should be something less than X.XXXe-10.

Given that your difference is exactly 1, I think the most obvious mistake might be in your calculation of numerator, denominator, and difference. Is your numerator equal to your denominator by any chance? Or is the difference correctly calculated from the numerator and denominator?