Hello Swastee,
UNQ C1 error:
Can I know why have you recalled cost_sum=0 outside the ###START CODE HERE and ###END CODE HERE
Refer this image to do correction accordingly
Error 2: Seems like you changed/ or alter the template code for compute_gradient cell.
See this image
Do the correction for this based on the below image
LET ME KNOW ONCE YOU HAVE PASSED THE GRADER.
Regards
DP