Not sure if it’s cause I’ve come back after working on something else but I’m failing to see how we relate insert stretching factor a into transformation T or how a “stretching factor” fits into the earlier examples, had a guess with
but got
so not sure what to do
ah issue was I was doing v @ T and not T @ v
am now struggling with understanding how we would reach (𝑥+𝑚𝑦,𝑦). in the next excercise
Yes, matrix multiplication (dot product style) is not commutative. The order matters.
yeah remembered that, was a little rusty, any insight on the newer question?
Work out what happens if you multiply the matrix [[a, b], [c, d]] times the vector [[x],[y]]. If it’s not clear what I mean by that notation, that is a 2 x 2 matrix dot a 2 x 1 vector, which gives a 2 x 1 vector.
but the fill in code for T has two sections for a 2*2 matrix?
Yes, there are 4 elements in a 2 x 2 matrix, if that’s what you mean. And how does that “play out” when you multiply T@v?
Did you do what I suggested there? What do you get? That shows you the fully general case. Now what do a, b, c and d need to be to get the answer you want?
ah ty, got through that one, gonna continue this tomorrow
Great! Yes, we’re in the same TZ. I’m gonna sign off for tonight as well. To be continued! 