Demento's Year 10 maths practice paper thread (6 Viewers)

[kev-kun]

Re: 2012 Year 9 &10 Mathematics Marathon

its a function

It doesn't say prove, it says explain why. This means it should refer to the definition of what a function is.

Ohhh lol didn't read question properly ==

 

[HSC2014]

Re: 2012 Year 9 &10 Mathematics Marathon

Someone needs to compose a BoS math olympiad for years 9/10 heehehe

 

[kazemagic]

Re: 2012 Year 9 &10 Mathematics Marathon

thanks smarty

be honoured

 

[Fawun]

Re: 2012 Year 9 &10 Mathematics Marathon

wait guys for questoin one c, when completing the square, did you get (x-4)^2 = -9?

or am i the only one who got a negative

and you can't square root a neg

 

[ganji]

Re: 2012 Year 9 &10 Mathematics Marathon

Do AMOC Correspondence Extension Program then... you get all the fun there ;P

 

[Fawun]

Re: 2012 Year 9 &10 Mathematics Marathon

So far i cant do question 1 a part 2, question c and question d

and it's only question 1

it's suppose to be easy

>ok

 

[HSC2014]

Re: 2012 Year 9 &10 Mathematics Marathon

wait guys for questoin one c, when completing the square, did you get (x-4)^2 = -9?

or am i the only one who got a negative

and you can't square root a neg

Yeah looks like there is no solution.

 

[Fawun]

Re: 2012 Year 9 &10 Mathematics Marathon

Yeah looks like there is no solution.

okay sweet because i thought i was the only one who got a no solution

 

[Fawun]

Re: 2012 Year 9 &10 Mathematics Marathon

for question e, there are roots? :S

 

[kazemagic]

Re: 2012 Year 9 &10 Mathematics Marathon

for question e, there are roots? :S

there shudnt be any roots O_O

 

[Demento1]

Re: 2012 Year 9 &10 Mathematics Marathon

Yeah looks like there is no solution.

Read the question more carefully.

 

[Fawun]

Re: 2012 Year 9 &10 Mathematics Marathon

there shudnt be any roots O_O

???

x^2 + x + 2 = 0

(x+2) (x-1) = 0

x = -2, 1

There are roots.

 

[Sy123]

Re: 2012 Year 9 &10 Mathematics Marathon

???

x^2 + x + 2 = 0

(x+2) (x-1) = 0

x = -2, 1

There are roots.

Expand your answer, you get a different constant

 

[Demento1]

Re: 2012 Year 9 &10 Mathematics Marathon

???

x^2 + x + 2 = 0

(x+2) (x-1) = 0

x = -2, 1

There are roots.

Mate, look. ^

 

[SpiralFlex]

Re: 2012 Year 9 &10 Mathematics Marathon

There's always roots. Some can be complex roots. But use the discriminant to test whether or not the equation has real roots.

 

[Fawun]

Re: 2012 Year 9 &10 Mathematics Marathon

Expand your answer, you get a different constant

wait expand the second line? :s

Mate, look. ^

what about it?

 

[Sy123]

Re: 2012 Year 9 &10 Mathematics Marathon

wait expand the second line? :s



what about it?

(x+2)(x-1)=0

x^2-x+2x-2=0
x^2+x-2=0

The question had positive 2 not negative 2

 

[kazemagic]

Re: 2012 Year 9 &10 Mathematics Marathon

wait expand the second line? :s



what about it?

its not x^2+x-2
it's x^2+x+2

 

[Fawun]

Re: 2012 Year 9 &10 Mathematics Marathon

(x+2)(x-1)=0

x^2-x+2x-2=0
x^2+x-2=0

The question had positive 2 not negative 2

idgi

So the question gives you an equation. You factorise it and then you have to expand it again which gives you the same equation but the constant with a negative. If I factorise the new equation, I still get the same thing. I'm going in circles here.

 

[HSC2014]

Re: 2012 Year 9 &10 Mathematics Marathon

Read the question more carefully.

Ah, minimum. Wasn't reading properly (sleep deprivation getting to me haha). In that case you do -b/2a for axis of symmetry and sub in for vertex.
Edit: Fail whale, didn't even read it had to be done by completing the square. *Scroll down for new answer