Completing square with fraction/decimal has come up before, but the transformation was much more complex than usual ones. Cylinder one was trickier than usual differentiation questions. But I wouldn't worry about your grade as it will be reflected in the grade boundaries. Posted from TSR Mobile
Yes the transformation part was the tricky part. I changed the bracket to (x - 0.5)^2 then added +4 to the end but I don't know whether that's right. I'm just hoping that the grade boundaries are lower than usual. Originally I was hoping for full UMS but I don't think I've got a chance now as I probabbly got around 62/75
For the transformation question, I ended up with an equation that went something like y = x^2 - 1/2x + 61/16, did anyone get anything similar, just want to know
I wrote down all the answers except for the "show that" ones on my Candinate Number slip Had very little room, so can't say which answer is which sub-question, only the numbered question.
1. Gradient = -3/5 Equation of perpendicular line: 5x-3y+1=0 Coordinate of A =(9,-4)
2. Gradient = 7+rt15
3. Tangent at A : y= -10x-4 Area under graph : 108/5 Shaded area: 270/5-108/5 = 162/5
4. Equation of circle : (x+1)^2 + (y-3)^2 =50 Centre = (-1,3) Radius = rt50 K = (-2,8) Shortest distance (C to QR) = 7
5. After completing the square : (x+3/2)^2 -1/4 Vertex = (-3/2, -1/4) Line of symmetry: x=-3/2 Translated graph : y=x^2 -x+4
6. h= 24/r - r/2 dV/dt = 24pi -3pir^2/2 r=4 d*2V/dt^2 = -12pi So a maximum value.
7. r=36 Factorised : (x+2)(x^2-5x+10) Only root: x=-2
3 small errors on cylinder question; Firstly I left the first part in the form (48-r^2)/2r, then I did not state r=+-4 (only positive 4, as that's what the question asked you to find) and finally I left the second derivative as -3(pi)*4 and then stated it was therefore a maximum. Would these lose marks?
I doubt you'd lose a mark for not saying r=+-4. As long as you stated the positive value it should be ok as the question said 'find the positive value of r'. However you'd probably lose a mark as you didn't say why it's a maximum. You have to say d2y/dx^2 < 0
Hi people..im an A2 student. Managed to get a hand on the paper and finished it in class. If you want me to send you the answers with working out just PM and ill send them
For the cylinder question I annoyingly left the answer as h=(48pi-pir^2)/2pir. I now realise it can be further simplified...How many marks do you think i will lose for this??
I dont know how many marks it was worth. but it asked to show that V equalled a certain form. thus, by not simplifyijg completely, you may not get the answer mark. although, in core one, there is a lot of condoning in the marks schemes.
Hi people..im an A2 student. Managed to get a hand on the paper and finished it in class. If you want me to send you the answers with working out just PM and ill send them
For the cylinder question I annoyingly left the answer as h=(48pi-pir^2)/2pir. I now realise it can be further simplified...How many marks do you think i will lose for this??
I left my answer unsimplified, exactly like you. However in the question it didn't say to simplify it, it only said to "find an expression for h in terms of r" so in my opinion I think you should get full marks. Let's hope it says OE in the mark scheme
Can you send to me please. And can you possibly include the marks for the questions and what the marks are for within the answers so ie) the ethos marks and answer marks (sorry it's a lot to ask)
I'm nervous although I got the area under curve and integral question write I wrote it as 648/30 which is equivalent to 108/5. But this could not get full marks apparently..could the boundaries increase? I reckon I got 50-52 but if the boundaries increase I might not get a C..
it was open top so the surface are was just pi r^2 + 2rh pi = 48 then you rearrange to get h=(48- pir^2) / 2r then you workout the volume equation which was v=pihr^2 then sub what you got for h into the equation and simplify
It was open top?! Why do I have an inability to read questions thoroughly? Not looking forward to core 2 lol
my teacher says "RTFQ" (read the effing question).
LOL I might start using that lol I tend to mumble "c0balt you idot read the f... Ahem question" in lessons With RTFQ no need to worry about slipping f word out of my mouth haha