0 grades in assigments

Code Cell UNQ_C1: Function ‘compute_cost’ is incorrect. Check implementation.
Code Cell UNQ_C2: Function ‘compute_gradient’ is incorrect. Check implementation.
If you see many functions being marked as incorrect, try to trace back your steps & identify if there is an incorrect function that is being used in other steps.
This dependency may be the cause of the errors.

This means your code for those two functions does not compute the correct results, for the tests used by the grader.