Question 28(a)(i) (1 Viewer)

[danger stitch]

Did anyone notice that this question didn't make sense? Was I right when I wrote that the expression given is wrong? Cos I'm pretty sure it was...

 

[Prime]

The expression is correct. XY is the area of the rectangle with the 2 there cause Y is only half of the side, (pie)y^2 is for the area of the 2 sides of the circle.

 

[Danni07]

I'd agree that it seemed wrong, I just tried to say something about it.
I thought the equation should've been X*2y + pi y^2

 

[danger stitch]

Ahhh fuck....took me so long and I couldnt work out why they'd done that. stupid me LOL

 

[Danni07]

The expression is correct. XY is the area of the rectangle with the 2 there cause Y is only half of the side, (pie)y^2 is for the area of the 2 sides of the circle.

Hmm... I know the y was half, but doesn't that 2 affect the x as well? *shrugs* I just answered it the same way as you did anyway.

 

[Prime]

Hmm... I know the y was half, but doesn't that 2 affect the x as well? *shrugs* I just answered it the same way as you did anyway.

Well I thought the same, but I worked it out both ways and it just...doesnt...queer maths.

 

[danger stitch]

I'd agree that it seemed wrong, I just tried to say something about it.
I thought the equation should've been X*2y + pi y^2

That's what I thought

 

[caligem]

yeah, that got me confused at first too, but actually it IS right how it is. what i did was i kinda tested my theory (x times 2y) against theirs (2xy) by assuming y=2 and x=6. In both cases the answer was 24, and i realised it didnt matter which way u wrote it, the result is the same.

 

[oranGez]

x times 2y is exactly the same as 2xy ...

just like 2 times y is exactly the same as 2y....

 

[Jayphen]

I got that right, and then went on to forget that "Y" was only HALF the length of the base of the pool in (ii) .. which resulted in me calculating the area covered by tiles completely wrong. doh.

 

[danger stitch]

oh well, i realise my mistake now. I didnt even bother trying to work it out mathematically. At least it was only one mark. Do they give out half marks in the hsc?

 

[Gummy_bear]

yeh, that q stuffed me around a little bit too.
i jsut wrote:
area of rectangle = 2xy
area of circle = 2(pie)r(squared)

i didnt know how they wanted us to prove it really.. i dont think ill get marks for that.
and no, you dont get half marks in the hsc, only 1 or zero.