SCHOOL CERT! Math free response last question (1 Viewer)

[shadow131]

What did you put.

Im talking about the one which askes for the expression for how many cubes (of all different sizes) are in this cube

I put

1^3 + ... + n^3

What did you guys put?

 

[Sculzyoner]

What did you put.

Im talking about the one which askes for the expression for how many cubes (of all different sizes) are in this cube

I put

1^3 + ... + n^3

What did you guys put?

Carin'... Honestly i had 10 min to go on that last page for Maths but i CBF, so i just slept for last 10...

 

[kr73114]

I also put that. 1^3+2^3...+n^3

 

[nehmch1]

yeahh im not sure if that was right but i putt that too =]

 

[Mythril]

Hey, it's nice to know that I'm not the only person who put down a similar answer. My answer was: 1^3 + 2^3 + 3^3.....+n^3 = total no. of cubes

 

[hul0]

i think i put 'n' and then my brain froze

=]

 

[Mudkip94]

Correct answer is: [n(n+1)/2]².

 

[BobMoo]

I put n^3+(n=1)^3+(n-2)^3...+(n-n)^3

But this is the proper answer got this from Brent012

Would never have thought dat =/

 

[Mythril]

I guess from the equation BobMoo listed out, if you wrote any of the three equations, you were right, since the three of them literally means the same thing as they are equal to each other.

 

[chevlr]

I put n^3+(n=1)^3+(n-2)^3...+(n-n)^3

But this is the proper answer got this from Brent012

Would never have thought dat =/

nah you only have to do the first part of that cos the rest of it is mathematical induction, which is a 3u topic, so they wouldnt want you to do it at sc

 

[Cee.]

By the time I did the last question, I had a brain fart. Didn't do it, who cares. Just one freaking mark.

 

[sonispucca]

my brain has died by then...
i made mine up, but still got it wrong -

3
(Integers >or equal to 1 <or equal to n)

 

[maths94]

i got 3n^2? is that correct

 

[silence--]

^no, not at all. that doesn't even work for n=1.

 

[khorne]

I put n^3+(n=1)^3+(n-2)^3...+(n-n)^3

But this is the proper answer got this from Brent012

Would never have thought dat =/

The problem is, you couldn't inspect the RHS and FRHS in an exam...so I think the accepted solution is the LHS.

Unless I am mistaken, by any means, post the full working.

 

[Hayzazz]

I put this
1³ + 2³ + 3³ + ... + (n-2) ³ + (n-1) ³ + n³

Hopefully I'll get a mark for it ^o^

 

[silence--]

yeah that will get a mark. the (n-2) and (n-1) weren't necessary though

 

[Hayzazz]

Meh, it makes the equation look more symmetrical :S

Symmetry is good.

 

[brent012]

The problem is, you couldn't inspect the RHS and FRHS in an exam...so I think the accepted solution is the LHS.

Unless I am mistaken, by any means, post the full working.

He just took that from my post and i just took it from wikipedia lol, if you want to read any more look here. Cube (algebra) - Wikipedia, the free encyclopedia

 

[FTW]

I thought for rules, they were looking for a specific formula, so I didn't think you were allowed to use a .... in your response so I had to make up something random and I put

n^2(2n-1)+n

which works in some instances, but tbh, I didn't know what I was doing, and I thought that was the hardest school certificate maths question I had come across.