Does anyone have mark scheme for OCR 2012 C3 paper January?

And does anyone knows how to solve this question

tan(θ + 60◦ ) tan(θ − 60◦ ) = 4 sec2 θ − 3,

it is from ocr C3 2007 June

Many thanks for help!

Use double angle formulae and identity sec^2x=tan^2x + 1

Reply 145

lamalas600

Anybody who wants jan 2012 i can email it to you if you give me your email

Say if you want mark scheme as well

Reply 146

Sem193

Original post by Aimanos

2G (review) question 7 g

I don't think I have the same text book as you :s-smilie:

Mine's endorsed by OCR and it has Cambridge written on it.

Reply 147

Aimanos

Original post by Sem193

I don't think I have the same text book as you :s-smilie:

Mine's endorsed by OCR and it has Cambridge written on it.

oohh yh mine says nothing about Cambridge. :frown:

Reply 148

simransanghera

hey has anyone done solomon paper H? I'm stuck on q4(b)

Thanks

Reply 149

dizzeedollee

Ah nevermind I worked it out myself :P

(edited 11 years ago)

Reply 150

Sweetcorn_1

Guys how do you do 8ii Jan 2012 C3. I really never leant how to do that type of question q_q

Reply 151

19hannah94

Anyone know how to do C3 Jan 2012 question 6ii?

Reply 152

Sweetcorn_1

Original post by 19hannah94

Anyone know how to do C3 Jan 2012 question 6ii?

make dy/dx = 4

solve (hint: try and get a single y on one side)

Reply 153

19hannah94

Original post by Sweetcorn_1

make dy/dx = 4

solve (hint: try and get a single y on one side)

Brilliant thank you!

Reply 154

ugk4life

what are grade boundaries usually for this paper?

Reply 155

mortaz786

Original post by ugk4life

what are grade boundaries usually for this paper?

50-55 for a (thats lowest from all core exams)
45-50 b
down in 3-5 from there on per grade

Reply 156

ugk4life

Original post by mortaz786

50-55 for a (thats lowest from all core exams)
45-50 b
down in 3-5 from there on per grade

cool, should be able to score a high A/low A* hopefully

Reply 157

19hannah94

Original post by Sweetcorn_1

make dy/dx = 4

solve (hint: try and get a single y on one side)

Could you do question 7bii by any chance?

Reply 158

lamalas600

Original post by Sweetcorn_1

Guys how do you do 8ii Jan 2012 C3. I really never leant how to do that type of question q_q

From the first part you know that

1-8\sin^2\theta\cos^2\theta=\cos4\\theta

Let's do some rearranging..

\frac{1-\cos4\theta}{8}=\sin^2\theta\cos^2\theta

It is given in the question that

\theta=\frac{1}{24}\pi

Plug that into

\frac{1-\cos4\theta}{8}

Reply 159

lamalas600

Original post by 19hannah94

Could you do question 7bii by any chance?

You know that it's mass is initially 40 grams, and 2years later 31.4 grams, and it's an exponential.

Therefore you know at time=0 (initially) it's 40 grams therefore M(40)=