Suppose that we use sigmod activation function and square loss function: (t- o)2. The learning rate is a. Derive the formulae for updating Vij and Wij using the gradient descent learning strategy in the backward propagation. For simplicity, we don't have bias in our neural network.

(For thought) a. A token of a computer language is any sequence of characters, with no intervening characters or white space, that taken as a unit has a unique meaning. Using this definition of a token, determine whether escape sequences, function names, and the keywords listed in Table 2.1 are tokens of the C++ language. b. Discuss whether adding white space to a message alters the message and whether messages can be considered tokens of C++. c. Using the definition of a token in Exercise 4a, determine whether the following statement is true: “Except for tokens of the language, C++ ignores all white space.”