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# D1 question watch

1. Ok so this is from a D1 past paper. For 6.b) why is 8 used to find the max. instead of 13

And for part c why does it have curves? I just drew the 4 straight sides of the shapeAttachment 614802614804
Attached Images

2. for part (b), you want to make the sum of the 4 shortest paths between each vertex as large as possible. We do this by making 3 of the paths as large as possible, and then putting every other edge between the last pair of vertices (as shown below)

for the last part it sounds like you were right, just draw in the unused ones in and ensure they are drawn so that they are not the minimum path between two vertices
3. (Original post by DylanJ42)
for part (b), you want to make the sum of the 4 shortest paths between each vertex as large as possible. We do this by making 3 of the paths as large as possible, and then putting every other edge between the last pair of vertices (as shown below)

for the last part it sounds like you were right, just draw in the unused ones in and ensure they are drawn so that they are not the minimum path between two vertices
I dont understand that first part - if you want to make it as big as possible then why not use 13 instead of 8?

Ahh ok i see what you mean, yeah i didnt include the unused edges
4. (Original post by kiiten)
I dont understand that first part - if you want to make it as big as possible then why not use 13 instead of 8?

Ahh ok i see what you mean, yeah i didnt include the unused edges
you want to make the minimum spanning tree as big as possible, the minimum spanning tree requires you to use the smallest edge between each pair of vertices.

Since you have to draw all the edges onto the diagram you have no choice but you use the length 8 in your minimum spanning tree, since its the minimum edge length overall.
5. (Original post by DylanJ42)
you want to make the minimum spanning tree as big as possible, the minimum spanning tree requires you to use the smallest edge between each pair of vertices.

Since you have to draw all the edges onto the diagram you have no choice but you use the length 8 in your minimum spanning tree, since its the minimum edge length overall.
Ah ok i see what youre saying now, thanks for your help
6. (Original post by DylanJ42)
you want to make the minimum spanning tree as big as possible, the minimum spanning tree requires you to use the smallest edge between each pair of vertices.

Since you have to draw all the edges onto the diagram you have no choice but you use the length 8 in your minimum spanning tree, since its the minimum edge length overall.
Hey, i have another question - do you know if any AQA past papers have had questions asking you to amend, complete etc. an algorithm? This is what the spec says:

"required to trace, correct, complete or amend a given algorithm, and compare or comment on the number of iterations required"

I wanted to try some exam questions on this but cant seem to find any. Ive only ever seen questions asking you to trace or state the purpose of an algorithm.
7. (Original post by kiiten)
Hey, i have another question - do you know if any AQA past papers have had questions asking you to amend, complete etc. an algorithm? This is what the spec says:

"required to trace, correct, complete or amend a given algorithm, and compare or comment on the number of iterations required"

I wanted to try some exam questions on this but cant seem to find any. Ive only ever seen questions asking you to trace or state the purpose of an algorithm.
Im afraid not, I havent done any D1 past papers yet. (im doing the module this year) but if I come across any in the coming months Ill let you know
8. (Original post by DylanJ42)
Im afraid not, I havent done any D1 past papers yet. (im doing the module this year) but if I come across any in the coming months Ill let you know
Oh haha lol i thought you were a lot older than me

Ill make a new thread and see if anyone else knows
9. (Original post by kiiten)
Ok so this is from a D1 past paper. For 6.b) why is 8 used to find the max. instead of 13

And for part c why does it have curves? I just drew the 4 straight sides of the shapeAttachment 614802614804
You will still get the marks if you draw straight lines, but normally in the textbook it shows curves when they draw the networks.

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