i got them too except for the vectors one. i found the co-ordinates of P to be (-2,1,0) I didn't know how to approach this question but i knew since that they were perpendicular, their dot product equalled zero. So i made a =(ai +bj +ck) and b = (-i-2j). Basically just used basic logic to get my answer. Really devastated with the Vol. of revolution, didn't have time to go back and check aswell because it took me three attempts on the proof. Anyone doing math at uni next year?
i'm really sorry to tell you this, but your co-ordinates for p don't fit on the line, as they don't substitute into the line equation.
I got the same co-ordinates (0,0,3) for P, but I used lamda, and got (2-lamda)i +(4-2lamda)j +3k, then worked that out as lamda =2. Are we on the same wave length here? lols
Yeah It's probably because there are multiple different equations you could have had for the line. I had r= i + 2j + 3k + t(-i - 2j) so you must of had something like r= 2i + 4j + 3k + lambda(-i - 2j) ?
i need 92% cos i want an a* seeing as i doing maths at queens nect year, so i need 180 marks between c3 and c4, and i only got 88 in c4, hence i need 92 in this
Got the same as you for the paperweight thing! 512pi over something lol
Sorry, think you may have got that wrong (hope so, otherwise I did :P). You had to find the volume when rotated 360 degrees between x-axis, the curve AND THE Y-AXIS (ie x = 0).
can someone who got q6. the vectors question fully right be able to upload their solution to i deduce how many follow through marks i might achieve, thanks!
can someone who got q6. the vectors question fully right be able to upload their solution to i deduce how many follow through marks i might achieve, thanks!
oh, perhaps i made a mistake with the limits, i used 2 and -2, although as i type this, i realise the question said between the y-axis, so should be 2 and 0
thanks bro, i messed up part ii). i just used the direction vector of the line l as the position vector OP. oh well, apart from that and the vol of revolution mishap it all went swell where are you for next year?
thanks bro, i messed up part ii). i just used the direction vector of the line l as the position vector OP. oh well, apart from that and the vol of revolution mishap it all went swell where are you for next year?
Still in school (unfortunately), doing further maths so sat the exam with the Year 14s. You?
How did you find the rest of the paper? I had given my maths teacher my answers for the questions and he did he paper and checked mine. The only answer of mine he wasn't sure of was the volume of revolution because he said the question wasn't clear. :P
How did you find the rest of the paper? I had given my maths teacher my answers for the questions and he did he paper and checked mine. The only answer of mine he wasn't sure of was the volume of revolution because he said the question wasn't clear. :P
Tbh I think I'm the same as you, ie the only one I know for sure I did wrong is the volume of revolution one due to the wrong lower limit! But I keep worrying haha eg in the one mark part of the vectors question, I'm not sure if I wrote it right? At the end of the day I probably did? But I worry nonetheless haha