Hello, I just started the machine learning specialization. I am currently trying to complete the practice lab assignment. As most of you are aware the assignment has two parts: One to write the cost function and one to define the gradient descent function. My code for the cost function is correct and it seems to pass the test code. The code is as follows:

# UNQ_C1

# GRADED FUNCTION: compute_cost

def compute_cost(x, y, w, b):

“”"

Computes the cost function for linear regression.

```
Args:
x (ndarray): Shape (m,) Input to the model (Population of cities)
y (ndarray): Shape (m,) Label (Actual profits for the cities)
w, b (scalar): Parameters of the model
Returns
total_cost (float): The cost of using w,b as the parameters for linear regression
to fit the data points in x and y
"""
# number of training examples
m = x.shape[0]
# You need to return this variable correctly
total_cost = 0
cost=0
### START CODE HERE ###
for i in range(m):
f_wb=w*x[i]+b
cost=cost + (f_wb - y[i])**2
total_cost=1 / (2 * m) * cost
### END CODE HERE ###
return total_cost
```

However, when it comes to the gradient descent function I seem to be facing issues when testing it out. I get an assertion error. I cannot fathom what could possibly be wrong in my code. My code is as shown below:

# UNQ_C2

# GRADED FUNCTION: compute_gradient

def compute_gradient(x, y, w, b):

“”"

Computes the gradient for linear regression

Args:

x (ndarray): Shape (m,) Input to the model (Population of cities)

y (ndarray): Shape (m,) Label (Actual profits for the cities)

w, b (scalar): Parameters of the model

Returns

dj_dw (scalar): The gradient of the cost w.r.t. the parameters w

dj_db (scalar): The gradient of the cost w.r.t. the parameter b

“”"

```
# Number of training examples
m = x.shape[0]
# You need to return the following variables correctly
dj_dw = 0
dj_db = 0
### START CODE HERE ###
for i in range(m):
f_wb=w*x[i]+b
dj_dw_i=(f_wb-y[i])*x[i]
dj_db_i=f_wb-y[i]
dj_dw += dj_dw_i
dj_db += dj_db_i
dj_dw=dj_dw/m
dj_db=dj_db/m
### END CODE HERE ###
return dj_dw, dj_db
```

What is wrong in the code shown above? I have completed the optional labs and everything checks out. Why do I still receive an assertion error?