OCR C3 exam 14th June 2012

The maximum for 5sin(x) is 5. So with the +C you had to figure out either way how it got to 43 or -37. When its maximum its +5, when its minimum its -5, so chuck an 8 in front go get to -40 or 40 then the +3 makes it either -37 or 43.

Reply 41

xX-ViK-Xx

i think i remember first 3 questions
1. modulus inequality question
2.i p=e^280 q=e^300 show that ln(ep^2/q)=261
ii 5^n>pq give biggest interger for n, think i got 361.
3 ai secxsinx=36cotx show that tanx = 6. x is acute?
bi exact value of tan(x+45)
ii exact value of tan2x

Reply 42

mini500

Seeing as sin(theta =53.whatever) = a negative number, you cant get a positive solution in the domain -180 to+180 as sin is only positive upto 180 degrees

Reply 43

tomfails

Original post by xX-ViK-Xx

i think i remember first 3 questions
1. modulus inequality question
2.i p=e^280 q=e^300 show that ln(ep^2/q)=261
ii 5^n>pq give biggest interger for n, think i got 361.
3 ai secxsinx=36cotx show that tanx = 6. x is acute?
bi exact value of tan(x+45)
ii exact value of tan2x

2ii) yessss i got 361, wasn't sure what it meant by integer so i rounded my answer up :L

Reply 44

alicatee

What did you get for the last 2 questions for:
9ii.) I got 0.5π(3e^4+1)
9iii.) I did the area of the rectangle (e^4) - my answer from part 2. But I realised that my answer was negative because we were working out the area outside of the curve so I did multiplied everything by -1 to get= 0.5π(3e^4+1) - (e^4)

Reply 45

tomfails

Original post by alicatee

What did you get for the last 2 questions for:
9ii.) I got 0.5π(3e^4+1)
9iii.) I did the area of the rectangle (e^4) - my answer from part 2. But I realised that my answer was negative because we were working out the area outside of the curve so I did multiplied everything by -1 to get= 0.5π(3e^4+1) - (e^4)

ii) agreed
iii) not a rectangle as far as i'm aware, it said rotated so it would have been a tube shape not a block... a tube with base of radius 2, and length the e thingy, then your answer at the end has pi as a factor out of all of it...

Reply 46

mcaley

c = 3 and k = 8. You had to use the fact that the max/min values of sin(theta) are 1/-1, and hence 5sin(theta) has max/min values 5/-5. Then split the inequality into two and solve :smile:

Nailed it.

Reply 47

alicatee

Original post by tomfails

ii) agreed
iii) not a rectangle as far as i'm aware, it said rotated so it would have been a tube shape not a block... a tube with base of radius 2, and length the e thingy, then your answer at the end has pi as a factor out of all of it...

Woops! I forgot to rotate around the x axis!! Oh well only 2 marks!

Reply 48

tomfails

Original post by mcaley

c = 3 and k = 8. You had to use the fact that the max/min values of sin(theta) are 1/-1, and hence 5sin(theta) has max/min values 5/-5. Then split the inequality into two and solve :smile:

Nailed it.

I'm hoping thats all it took, if so that question was easy, I reckon there may have been more too it but hope not :smile:

Reply 49

donaldkng

anyone going to upload the paper?

Reply 50

tomfails

Original post by alicatee

Woops! I forgot to rotate around the x axis!! Oh well only 2 marks!

Exactly

not to worry, you got the bit before for 6 marks right :biggrin:

or we both got it wrong....now core 4 :angry:

Reply 51

|Alex

4

I completely lost my head for the very last question. I read it as basically you had to rotate around the y-axis between x=0, x=2 and y=0.5. With no upper limit I thought the answer was just infinity dunno what I was thinking

Reply 52

oic_2006

this paper was so easy your all numbskulls LOL :smile:

Reply 53

oic_2006

looool jokin i found it okay apart from a few questions such as the constants c and k question!!!

Reply 54

thedonstudent

Original post by oic_2006

this paper was so easy your all numbskulls LOL :smile:

loooooool

Reply 55

ZoeK123

Did 9ii say rotate around the y axis??? D=
I rotated it round x ¬_¬

(edited 11 years ago)

Reply 56

crowld

9ii) 3/2(pi)e^4+1/2(pi)?

Reply 57

ZoeK123

Original post by crowld

9ii) 3/2(pi)e^4+1/2(pi)?

Yeah that one

Don't tell me it didn't even say to rotate it...

(edited 11 years ago)

Reply 58

McMatty

Anyone got the answers yet?
Didn't put exact values for the last two i don't think! :/ ahh well

and for the 2ii) question to find N, you had to find the first integer so it was like 361 or summin? rather than the 360.343423424234234... or whatever

Reply 59

tomfails

Original post by McMatty

Anyone got the answers yet?
Didn't put exact values for the last two i don't think! :/ ahh well

and for the 2ii) question to find N, you had to find the first integer so it was like 361 or summin? rather than the 360.343423424234234... or whatever

361 correct :smile:

OCR C3 exam 14th June 2012

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