Hi all,

Just posting to give an update. I think my problem is too easy I had it pretty much figured out in my head, it would take me not too long to write it out after that. I think I need a new idea (Danny, any ideas?).

I seem to be understanding the course work. I haven't had much time to commit to it as life has gotten in the way. When I'm in class it all falls into place in my head. I didn't do so great on the midterm, but it's due to a common problem with me, things seem so obvious to me that I don't write them down and then I lose marks for not writing them down. But I am doing really well on the quizzes so it's not so bad.

So long for now,

Wendy

Mathematical Problem Idea

Hi all,

I think I have figured out what I will do for the mathematical problem I need to solve on this slog.

My idea is: to prove that a number is a multiple of 11 if starting from the right you take the first digit, then subtract the second digit, then add the third digit, then subtract the next and so forth; then if that number is a multiple of 11 (positive, negative or zero) then the original number is also a multiple of 11.

I think this might be able to be proved using complete induction. I see a few problems arising. One is proving that the number I get in the add subtract step is smaller than the previous number always (although I think I sorta see how to prove that). Another is how to prove that if the new number is a multiple of 11 the previous one is also. After that it could be fairly straight forward. I guess part of it will be seeing it in action with numbers where the add subtract step gets a number >= 11.

By the way I got this algorithm from http://www.counton.org/explorer/primes/divisibility-tests-for-9-and-11/

So long for now.

Term Test Complete!

Hello,

So the term test is done and it was very straight forward. I think I have this induction thing down.

The next topic looks to be a bit more challenging. Seeing as I haven't seen big-oh in 4 years. I think I'll pick it up as I go and it is slowly coming back to me.

Looking at the floor and ceiling stuff will be need a bit of a refresher. I seem to remember that floor(x) > x - 1 and ceil(x) < x+1. I seem to remember learning that in CSC165 many moons ago. Also floor(x) <= x and ceil(x) >= x.

The definitions of ceil and floor are:

ceil(x) = :
x  if x is an integer
x + (1 - (x mod 1)   otherwise

and floor(x) = :
x if x is an integer
x - (x mod 1)  otherwise.

It seems that last class suggests I should figure out some properties of these operators beyond that.

So long,

Wendy

Week 4 Begins

A quarter of the way through the semester ALREADY. It always goes so fast.

Last week I got my first assignment for this course done. I didn't have a lot of difficulty with it.

I was impressed with myself with the way I solved question 4. Instead of combining the two related claims about binary strings, I proved only the claim about strings beginning and ending with the same bit. I accomplished this through my induction step. I went to the next string by inserting an arbitrary bit in the center (or Ceil(n/2)), thus preserving the same bit at each end. I thought this was clever.

I can see how one would prove this using the combined claim, but I wanted to see if my way would work and it did!

My plans for this week are to start the tutorial #2 problems. I have looked them over, I just haven't sat down to work them out. This is assuming my CSC209 assignment won't hog all my time. At least I got the assignment for this course finished so I'm not rushing on that.

On a side note, I wish my door didn't let in so much noise so I could still be asleep.

So long.