x^2 - 10x + 18 = (x-a)^2 + b
To find a and b.
Uproar on a local forum that the SQA Scottish Standard Grade exam contained this and that it was a Higher grade question. Well if this is uni entry standard i.e. Higher than I don't know what this country is coming to...
I hope so
Do it!
I don't really understand the problem
It's completing the square. The same thing's on the A-level maths syllabus. It's a bit walked-through perhaps, but that's it.
OH YEAH
now i remember.
easy fucking question. IF I COULD BE BOTHERED.
well, it's pretty unfair to expect people who haven't been taught how to do it, to y'know, answer th
and anyway, that's one of the simplest questions (eie. worth 2/3 marks) that was on the higher paper when i sat it last year.
for the record, i can make it to about the third or fourth line of working and then i can't remember what i'm meant to do after it. OH NOEZ HOW WILL I POSSIBLY GET AHEAD IN LIFE????????
the bloody thing*
DA ANSWER IZ
23827878
the answer is 17
it's ALWAYS 17!
I reckon if you put 42 as every answer on a maths/physics paper
geek solidarity means they'd at least have to give you a D.
:D
I did a class called Exploring the Cosmos in first year uni. The class test was worth 20% and was completely multiple choice.
Statistically, if you put A, B, C or D for every answer you were very likely to get 25%.
I preferred to draw pretty pictures with my multiple choice guesses.
Those sort of tests
usually use negative marking so you'd usually average 0 though. Ours always did.
nope, i can't
a 16 year old should be able to do that
...
my thoughts exactly lyle
^ Yep,
but I wouldn't expect an over 16 year old who hasn't touched a maths book in years to be able to do it.
If you can then big fucking whoop.
i can!
i got an A in higher maths. i'm surprised i remember this though. I thought uni level maths took off from advanced higher maths rather than higher maths though. if i tried to do maths at university i would FAIL.
its ok for things like this to slip into standard grade i suppose to distinguish the wizz kids, since its such an easy paper. the SQA are silly anyway...
i think that was only worth a couple of marks in higher as well and is one of the easy non-calculator ones.
what does this ^ mean?
The "^" in the maths question?
to the power of.
I could porbably have done this
2 years ago, but I've spent so long not doing maths I forgotten it all :(
To the power of, presumably
oh.
how I got an A in GCSE maths is completely beyond me. I have no idea where to even begin with that problem.
a's in teh brackets after the x and b's at the end.
Damn
I thought I could remember how to do this, but so far all I've got is:
18-10x = a(a-2x)+b
Which doesn't help anything, I think...
Just over two years ago I was doing higher maths at A level, but already forgotten it all. Damn.
im now 25
i wouldnt even know where to start anymore.
a=5
b=-7
^alan turing
I'm sitting advanced maths a week on tuesday
then no maths EVER AGAIN!
YAY!
Anybody who's done A-level maths
should be able to do that no problem. Even if you don't now the 'proper' method for solving it just multiply out the right hand side and it becames obvious what a and b are.
I didn't do anything further than standard grade maths.
So, I probably couldn't do this, no. :(
nope not a chance
I only made it as far as scraping a C at GCSE - I'd stand a better chance of reading French and I haven't done that since I was 13 or 14.
this is awful
I got A* at GCSE, A at A-Level (needing -3 when I sat my last paper), and I don't have a fucking clue how to do this :( Someone explain?
Well as it's (x-a)^2
that is basically (x-a)(x-a)
I.e when multiplied out becomes
X^2-2ax+a^2
as -2ax corresponds with the -10x on the other side, equate the coefficients
-2a=-10
a=5
then you put that into the main equation and you get 25, so you have to minus to get 18, therefore b=-7
pretty easy.
yeah but
how can you just take the '18' and 'b' term out of the 'main equation' like that?
Surely if you multiply out the brackets you get
x^2 - 10x + 18 = x^2 - 2ax + a^2 + b
from there, how do you argue that "-2ax corresponds with -10x on the other side"?
because "-2ax" is the only term on the other side containing an x term
yep
you're right. Absolute concrete proof that I don't remember anything from A-Levels.
Like I said
I don't know if this is the 'proper' way that people are taught but multiplying out the right hand side you get x^2 - 2ax + 25 + b.
You see on the left hand side you have a 10x therefore 2a = 10 so a = 5
Also from the lhs you see you have 18 added to the x^2 - 10x, therefor 25 + b = 18 so b = 18 - 25 = -7
I do a-level maths
yet I Don't understand ANY of this.
I'm so going to fail :(
it's pretty common to include
questions that would usually be 'above' the level of teaching, to highlight those who have indulged in extra study
it seperates the A's from the A*'s
No
I wouldn't even know where to start.
That's not even remotely hard
I don't get it.
Why is there outrage? It's just really basic foundation stuff, you'd expect it to be in a test as a starter but it certainely isn't difficult.
Is higher GCSE or A-level?
Higher is in between GCSE and A level
Oh right
sounds about right then.
maths
Maths is mainly silly. you only need the basics.
that's not true
it is true
Even accountants can get by with the basics. they don't need algebra or pythagorus or whatever.
Accountantcy is not the height of mathmatical application
accountancy
My dad's a high-flying city type Finance Director
He left school with only a handful of O levels, failing maths. 40 years later and he's on a six-figure salary, but he still doesn't understand algebra.
Yeah
That's not surprising. If he was an engineer or something it would be.
I have no idea now
as I haven't used Algebra for years.
A few years back when I was using it at A-Levels/Uni I would probably have had no probs.
I suppose that's the problem of learning things you never use.
Not a chance
but as I haven't touched any maths problems since I got a lowly 'C' at O level 24 years ago (yes I'm that old!) I'm not that bothered!