[Roelof]

Originally Posted by ppaquay

Hi,

You could also check out my solutions to the book problems on GitHub :

https://github.com/ppaquay/Learning-from-Data-Solutions

Best regards !

In problem 1.3(c)
you make the step:

||w(t-1) + y(t-1)x(t-1)||^2 = ||w(t-1)||^2 + ||x(t-1)||^2 +2 y(t-1)w^T(t-1)x(t-1)

What lemma are you basing this step on?

You can prove by simple algebraic manipulation (so no need for use of a lemma) by using w(t)=w(t-1)+y(t-1) and the definition of ||w||^2 namely, w^T w