Maths ext 2 trial (1 Viewer)

peepeepoopooo

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Completed the CSSA Maths ext 2 trial on Monday was curious of what other people thought of it, I found most of the q)16 very challenging except for the cos integration
 

xoNat

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Completed the CSSA Maths ext 2 trial on Monday was curious of what other people thought of it, I found most of the q)16 very challenging except for the cos integration
I found it really challenging
Walked up to this girl in my class after and we just started laughing
 

tywebb

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Well I thought they could have found a better way to find the minimum distance between skew lines.
Here is my alternative solution to 15ciii which is much more efficient than the method in the paper, and also doesn't rely on any previous parts either.
15ciii-alternative.png
 

tywebb

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Hey how about 16a. The official solutions are very long. You can do it in 1 line like this:

16a.png
 

tywebb

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Here is another shorter way, but less algebraic, more of a combinatorial approach.

if you have m girls and n boys, you can line them up in m!n! ways such that all girls come before all boys, and in (m+n)! ways without that restriction.

Hence m!n!<(m+n)!
 

Average Boreduser

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They took 8 pages to get up to 12b. I did all that in 1 page. Here are the rest of my solutions, many of which are quite different to the official ones


Haven't checked for typos though. I'll do that tomorrow.
wait so why did u use hyperbolic trig for 7.? Wouldn't that require you to prove its properties to actually use it? Wouldn't it be easier to use in syllabus mthods? I was just wondering since theres already complexity in there being hyperbolic trig, but now theres also a complex number inside the function so like surely this wouldn't suffice in a real exam?
 

tywebb

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wait so why did u use hyperbolic trig for 7.? Wouldn't that require you to prove its properties to actually use it? Wouldn't it be easier to use in syllabus mthods? I was just wondering since theres already complexity in there being hyperbolic trig, but now theres also a complex number inside the function so like surely this wouldn't suffice in a real exam?
makes it quicker

cosh(ix)=cos(x)
 

tywebb

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also you know it is going to be much easier if the i is in the cosh than if it isn’t

think about it

what is going to happen if the i is in the cosh? imaginary parts cancel and it simplifies

what is going to happen if the i isn’t in the cosh? nothing! so nothing cancels.
 

tywebb

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