Q: I heard a rumor that Program #6
isn't due until Wednesday.
A: Yes, it is still useful to go to
lecture. Glinert spent 1/2 hour on Monday's lecture going over Program #6
and finally ended with an extension for everyone until Wednesday.
Furthermore, if you hand it on Monday, you will get the bonus points.
Q: For program #6... how does this
whole thing work? I don't understand Glinert's explanation. DOH!
A:Consider zis puny example:
Let's say you are working on the following equation:
And you choose V to equal 100.
Then A = -100 and B = 100
For the first time through, C = 0 (because C = (A+B)/2.0 )
But that is alright. P(C) will just equal 24
Since 24 is positive, you will have to check if P(A) or P(B) is positive. If P(A) is positive then A = C otherwise B = C.
Since, in this case, the value is positive, we will replace the B.
So now you run through the whole thing again with A = -100 and B = 0
Do this until you get really precise numbers for A and B. Like A=-4.6827435 and B = -4.6827438.
Then choose one, say A, and that will be the approximated root.
Your output should show all of these iterations and run through all 6 equations Glinert gave you.
Q: How do you use redirection?
A: Here me now and believe me later,
redirecting a file will make your life much easier.
First just make your program as usual, with the normal cin statements. Then create a file, called data, that looks like so:
2 4 -20 24
-6 1 3 -40
1 20 30 40
4 13 0 -13
100 13 -13 0
-3 1 -20 25
0
Where each of the numbers corresponds to a, b, c, and d. The final
0 in the a slot will tell the program to end.
Now run your program with the UNIX command:
cubicRoot < data
This way you can run your program quickly without having to type in all those numbers over and over again.
Q: Do we have to find all 3 roots
for each problem?
A: Only equations #4 and #5 (from
the standard data) have 3 roots, all the others only have one root. But
for #4 and #5 I will accept any one of the 3 roots as being the correct
solution.
Q:
I am running out of space on my account. I don't want my homepage anymore
and it is taking up space. Are we going to be graded on it again or
can I remove it? Mmmmm, disk space...
A: Zee homepage may be terminated.