PC2 Maths, AQA 24/05/10

I found it odd they asked about the circumference too... its 2*pie*r ?
Never saw that in a paper

Also, how did show there was no maximum point? (It said "hence" and was 2 marks)

Reply 81

rob...

OP

I think the last log quesitnon was 3, i remember it being stupidly low!

Reply 82

lifeadd1ct

Guys, I don't understand where you are coming from. In the last 2 log questions, you had to get an answer given in the exam. The very last question, you had to get 1/(4log2) as the answer.

Reply 83

Averagegirl:)

I bet the examiners are just sitting in their armchairs chuckling to themselves as we speak. I didn't even know we were meant to use our answers from the previous question, they usually say 'hence...'
This sucks.

Reply 84

rob...

OP

I think for the circumfrence it said the circumfrence of another circle or radius x m, is the same as the area calculated in part b, whats x?

so one takes the area (27.2? or 72.7?) nd dividews by 2*pie i think.

Reply 85

*A_S_H*

the last part of the last question was a killlerrrrrrr uffffffffffff i lost 4 marks already

Reply 86

lifeadd1ct

rob...

I think for the circumfrence it said the circumfrence of another circle or radius x m, is the same as the area calculated in part b, whats x?

so one takes the area (27.2? or 72.7?) nd dividews by 2*pie i think.

Yes, that is correct. You must make the following equation

27.2=2pie r

and solve for r

Reply 87

Phalange

rob...

I think for the circumfrence it said the circumfrence of another circle or radius x m, is the same as the area calculated in part b, whats x?

so one takes the area (27.2? or 72.7?) nd dividews by 2*pie i think.

Phew yeah it was perimeter I think. Something like 27.2 yeah. I remember r for the sector was 8 and theta 1.4

Reply 88

Averagegirl:)

rob...

I think for the circumfrence it said the circumfrence of another circle or radius x m, is the same as the area calculated in part b, whats x?

so one takes the area (27.2? or 72.7?) nd dividews by 2*pie i think.

Yup, that is what one should have done. :yep:

Reply 89

*A_S_H*

Phalange

I found it odd they asked about the circumference too... its 2*pie*r ?
Never saw that in a paper

Also, how did show there was no maximum point? (It said "hence" and was 2 marks)

if u find the second deffrential then substitue that x=1 value , it worked out to be positive , (greater than 0) so it wasnt a maximum i hope dats right becuase thats what i wrote

Reply 90

Averagegirl:)

Does anyone remember what they got for question seven when you had to solve cos(2x)=1/2 ?

Reply 91

Phalange

*A_S_H*

if u find the second deffrential then substitue that x=1 value , it worked out to be positive , (greater than 0) so it wasnt a maximum i hope dats right becuase thats what i wrote

LOL NOOOO I solved it for =0 and it was positive so I said no maximum as its a minimum
********
grrrr

Reply 92

Jono404

13

Yeah i think i did

2(pi)x=27.2
(pi)x=13.6
x=13.6/pi
x=4.33 to 3sf

Reply 93

Phalange

Averagegirl:)

Does anyone remember what they got for question seven when you had to solve cos(2x)=1/2 ?

0.4 and like 2.6
something like that... answers in radians i think

Reply 94

lifeadd1ct

*A_S_H*

if u find the second deffrential then substitue that x=1 value , it worked out to be positive , (greater than 0) so it wasnt a maximum i hope dats right becuase thats what i wrote

You had to let dy/dx equal zero and find the x value and substitute into d2y/dx2. Then you get a positive answer hence the stationary point is a minima

Reply 95

Zeento

2

For questions seven i kept getting 0 and it wouldn't equal half! and i forgot the bludy circumference of a circle thats not fair :frown:

wwsnt in any pasp papers. feel like i got everyhting wrong ..

Reply 96

Phalange

lifeadd1ct

You had to let dy/dx equal zero and find the x value and substitute into d2y/dx2. Then you get a positive answer hence the stationary point is a minima

It was only 2 marks I didn't think you'd have to go through all of that
ah well

Reply 97

Jono404

13

Phalange

0.4 and like 2.6
something like that... answers in radians i think

Arghhh, you sure it wasn't 0.5 something? cause the 2x values were like 1. something and 5.something then you halve them

Reply 98

*A_S_H*

lifeadd1ct

You had to let dy/dx equal zero and find the x value and substitute into d2y/dx2. Then you get a positive answer hence the stationary point is a minima

ohhhh i substituted x=1 :frown:

Reply 99

Zeento

2

lifeadd1ct

You had to let dy/dx equal zero and find the x value and substitute into d2y/dx2. Then you get a positive answer hence the stationary point is a minima

How many marks were on that question? Seems like that's the onlt one i got correct at the moment..

PC2 Maths, AQA 24/05/10

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