[tooambitious]

(Original post by FK_)
1i) Draw the diagram with 10 arcs
1ii) Complete Dijkstra's algorithm. Length = 49 Route : AEF
1ii) Time = 1200 seconds

2i) Draw a pentagon (eulerian with 5 arcs)
ii) 5 arcs, 5 vertices, semi-eulerian, one vertex with order 4 - hence join the vertices with order 1 together
iii) 5 arcs, 5 vertices, semi-eulerian (none order of 4).

3i) Connect up the subjects
3ii) The two odd nodes, D1 and M2 had to be in separate sessions. For the rest, you had to just following the arcs through.
iii) An arc is added between M1 D1 which forms a loop of 3 arcs. Explain logically why this is impossible.

4i) Simplex Question: add 'slack variables' and make equations with equals signs. The restrictions on s,t and u were that they had to be greater than or equal to 0
ii) iii)... Answer was 26.4
Slack for S was 2, hence there is 2 left other in constraint 1 (or something to that effect).

5i) Linear programming question - find equations of the lines
ii)Find optimal point
x=4/3
y=8/3
iii) Integer solution: x=2 and y=2 which gives a value of 12? for P...

5i) Can't remember. Find lower bound and upper bound etc.

6i) X=-0.2
ii) X decreases by 1 and goes back to X=0
iii) The algorithm gives the same root as in part i but with more decimal places and ridiculous fractions (what is the point in that question?)
iv) The algorithm has no counter. Hence, if the cubic has no real roots, the algorithm will go into an infinite loop

Seems right, except las question, cynics always have at least one real root

[icy elemental]

For the last equation I just put with larger numbers it can be very time consuming xD Pretty certain I dropped that mark, I think the actual answer was it doesn't give a particularly accurate answer (using calculator functions to factorise the cubic gave an answer about 0.25 lower than the algorithm did) due to the margin for error in -0.05 - 0.05

[tooambitious]

(Original post by Nathdragon5)
Yeah, same here, that'd be amazing to get 100 when you know you screwed up well, best of luck to you!

Yeah I wasted so much time misreading the question, good luck to you too

[tooambitious]

(Original post by icy elemental)
For the last equation I just put with larger numbers it can be very time consuming xD Pretty certain I dropped that mark, I think the actual answer was it doesn't give a particularly accurate answer (using calculator functions to factorise the cubic gave an answer about 0.25 lower than the algorithm did) due to the margin for error in -0.05 - 0.05

Lol I wrote exactly the same hahaha

[FK_]

(Original post by tooambitious)
Seems right, except las question, cynics always have at least one real root

Thanks, i realise now that I was thinking of the shape of a quartic not a cubic. Plus complex roots also come in pairs which makes sense now.
. Do you mind me asking what you put?

[mortaz786]

(Original post by FK_)
1i) Draw the diagram with 10 arcs
1ii) Complete Dijkstra's algorithm. Length = 49 Route : AEF
1ii) Time = 1200 seconds

2i) Draw a pentagon (eulerian with 5 arcs)
ii) 5 arcs, 5 vertices, semi-eulerian, one vertex with order 4 - hence join the vertices with order 1 together
iii) 5 arcs, 5 vertices, semi-eulerian (none order of 4).

3i) Connect up the subjects
3ii) The two odd nodes, D1 and M2 had to be in separate sessions. For the rest, you had to just following the arcs through.
iii) An arc is added between M1 D1 which forms a loop of 3 arcs. Explain logically why this is impossible.

4i) Simplex Question: add 'slack variables' and make equations with equals signs. The restrictions on s,t and u were that they had to be greater than or equal to 0
ii) iii)... Answer was 26.4
Slack for S was 2, hence there is 2 left other in constraint 1 (or something to that effect).

5i) Linear programming question - find equations of the lines
ii)Find optimal point
x=4/3
y=8/3
iii) Integer solution: x=2 and y=2 which gives a value of 12? for P...

5i) Can't remember. Find lower bound and upper bound etc.

6i) X=-0.2
ii) X decreases by 1 and goes back to X=0
iii) The algorithm gives the same root as in part i but with more decimal places and ridiculous fractions (what is the point in that question?)
iv) Unsure

for 6i) wasnt it that w had to = between -0.05 and 0.05...... -0.2 isnt in that range.. i got that and then started another cycle by placing -0.2 as the input

[icy elemental]

No, it was that W - X had to be in that range, a lot of people I know did that wrong.

[FK_]

(Original post by mortaz786)
for 6i) wasnt it that w had to = between -0.05 and 0.05...... -0.2 isnt in that range.. i got that and then started another cycle by placing -0.2 as the input

Yea I mentioned this before on page 4 of this thread. I'm pretty sure it's 0.2 but I could be wrong ofc

[Nathdragon5]

(Original post by icy elemental)
No, it was that W - X had to be in that range, a lot of people I know did that wrong.

Yeah, this is right, that's what I did, and the algorithm just kept going, luckily I realised before the end tho :P

[mortaz786]

(Original post by icy elemental)
No, it was that W - X had to be in that range, a lot of people I know did that wrong.

ye but w was -0.2 and x was 0.... that stil = -0.2

[icy elemental]

(Original post by mortaz786)
ye but w was -0.2 and x was 0.... that stil = -0.2

Yeah, so you do it again replacing X with -0.2 and that time it ends.

(Original post by Nathdragon5)
Yeah, this is right, that's what I did, and the algorithm just kept going, luckily I realised before the end tho :P

Pretty sure it didn't keep going... when you start with X = 0, it ended within two run throughs of the algorithm. With X = -1 it ended within three.

[eliotball]

(Original post by Lucozad)
Random Guess of grade Boundaries

A - 52
B - 47
C - 42
D - 37
E - 32

way optimistic

[hf175]

(Original post by FK_)
Surely for the second iteration:



Therefore

Oh. Yet another silly error I made. Hopefully I won't loose too many marks for doing another iteration.

[kofanov]

(Original post by eliotball)
way optimistic

that can't be true at all.... see this:http://www.ocr.org.uk/news/2011/item_005.html#nogo

[h2shin]

wow, that went a lot worse than expected.
I got 600 for upper bound anyone else?
I couldn't finish the last part of first question so just put -0.217 as a guess ?

and for the very last question, I put if guesses are not far away enough from each other you will get the same result.

[Astronemma]

uuurg that was awful, I didn't finish in time :/
So annoyed at myself that I missed that you had to convert it into minutes, easy mark lost
And Simplex should have been for waaay more marks... :/
Think I'll be lucky to get a D... but considering I only had about 5 lessons for it and taught myself most of it, I think I'm OK with that... :L There's always a resit in January!

[Lucozad]

(Original post by h2shin)
wow, that went a lot worse than expected.
I got 600 for upper bound anyone else?
I couldn't finish the last part of first question so just put -0.217 as a guess ?

and for the very last question, I put if guesses are not far away enough from each other you will get the same result.

i got 600 tooo

[h2shin]

(Original post by Lucozad)
i got 600 tooo

yay !
I was worried cause I accidently did the prim's algorithm to start with so I panicked and rushed the nearest neighbour.

[bigsam]

did anyone get 590 for the nearest neighbour question?

[Abblecrumble]

Wow, it was so time-consuming! ♥
The algorithm and simplex took so long...
It looks like everyone has had similar problems though, so hopefully it will be ok! Haha.