Q1.1: Forward Pass

Suppose that

[0.4

0.3 0.9 0.3b"=1,1,1); and

0.2

2

= 0.2, b²=0.5).

0.8

If the input is a =1). what is the network output? Show your calculation steps and round your

answer to 4 decimals.

[Answer]

Q1.2: Backward Propagation

Use the chain rule to derive the expressions of the following gradients:

1.

2.

ƏL

dwz

ƏL

owl

and

and

ƏL

ab²)

ƏL

ab¹

Your final answers should only include the variables appeared in the question.

Hint #1: Begin by writing down the chain of partial derivatives, and then plug in predefined

variables.

Hint #2: While plugging in predefined variables, be careful about the dimensions and

orientation. You can first write down the expressions in the element level and then figure out the

matrix form.

Hint #3: The derivative of a (x) is a (x)(1-o(x)).