graphics calculater solver (1 Viewer)

[`|<|2o|\|aLd`]

I was wondering if we have to show working out on questions like this:

A sphere has a volume of 115m. What is its radius?

Its a 2 mark question and you can just type 115=4/3 (pie) R^3 into the graphic caculater equation solver. Would we still get the 2 marks or what?

 

[Happeninchick]

Good question actually... I was wondering that too. It seems that General markers want to see all our working out, for some crazy reason. I like taking short cuts too, so I have been practising writing everything out. Probably the best thing to do is write out the formula that you will enter into the calculator, just so they know you understand the whole formula aspect. If anyone can help, that would also be great - cause I don't really know myself...

 

[cro_angel]

wow graphics calculators just solve equations? thats so cool
but its easy to finish the exam in like 2 hours 10 mins when there is all working out shown.. damn u guys must finish heaps quicker
i guess its better to be safe then sorry.. but call the advice line it opens in like 20 mins

 

[PC]

Graphics Calculator Solver

If you're going to use the "solver" to do some sort of equation, the best thing to do is to write out the equation in the question. Underneath that write down the values that you're given ... the ones that your going to put into the calculator. Then try your luck with the calculator and give the answer.

BUT BE CAREFUL!

The calculator will give you the right answer about 95% of the time, but it's just number crunching, and depending on how complex the equation is it may not be able to find an answer, or may even give an incorrect answer (it will be the calculator's best attempt at the solution before giving up). You may need to change the "starting value" of the number you're trying to find, to give the calculator a bit of a hint.

 

[`|<|2o|\|aLd`]

wow graphics calculators just solve equations?

Yeah i think theres also a tetris game on them somewhere too.

 

[paganinio]

IMO,
for simple question, you may need to write every step out.
for question including many steps, you can skip some of them.

 

[Slidey]

I was wondering if we have to show working out on questions like this:

A sphere has a volume of 115m. What is its radius?

Its a 2 mark question and you can just type 115=4/3 (pie) R^3 into the graphic caculater equation solver. Would we still get the 2 marks or what?

A sphere is a volume of revolution, specifically a circle of revolution, x^2+y^2=r^2, or solving for y^2,

y^2=r^2-x^2=f(x)^2

Then the volume of a sphere is the integral from 0 to 2r of pi*f(x)^2, so pi*[r^2.x-x^3/3] from 0 to 2r, which works out to be pi*[2r.(2r)^2 - (2r)^3/3] = pi*[4r^3 - 8r^3/3] = 4pi.r^3/3.

So the volume of a sphere of radius r is 4 * pi * r^ 3 / 3 or 4pi.r^3/3

So now that we have derived the volume of the sphere, and since we are told what it's volume is quantitatively, we equate the two and since we want the radius, we solve for r:

(First, I am presuming you mean it has a volume of 115m^3, not 115m, which would be pure nonsense)

115=4pi.r^3/3
345=pi.r^3
r^3=345/pi

The principle, and only real value of r = (345/pi)^(1/3) metres. #

 

[Gummy_bear]

HI, i just thought i say a bit on this.
say if you have a simple question like that spere one you mentioned, and you dont do any working, if you accidently type a 6 instead of a 3, or you put the decimal in the wrong place you will get zero for that Q.
BUT, if you show the working and it is the right working for that Q, but your answer is wrong for sum silly reason, you will actually get one mark, even though the answer is wrong, the markers take into account that you may have simply typed sumthing wrong.
if you get the answer right and show the working you will get full marks.

there is probibly no point in showing working if you KNOW that you will get every answer completely right, but no one can be sure of that.
this was told to me by my maths teacher, who has been marking the HSC for quite a while, so im pretty sure hes right.
i hope that has helped.
though im not sure exactly what they'll do if you do the working, make a silly mistake and its a one point answer, coz i think they cant give you half marks in the HSC...
i think they give you full anyway..
oh well