[Official Thread] OCR MEI AS Mathematics 2016 (C1, C2 & S1)

Original post by Studious_Student

i) When a = 5 the sequence oscillates, so the remainder would be 2, x 5 = 10 for the second term, the 3rd term would be 1 since 10/3 has a remainder of one, x 5 = 5 for the third term, this goes back to 10 for the fourth term. 10+5+10 = 25.

ii) When a = 6 there is no remainder to multiply by 5, so the sequence would be 0,0,0,0. the sum of these would be 0.

Thanks

Reply 781

Slenderman

2

Original post by ♥Samantha♥

What are you serious with that log question? I put -3m! Wtf is wrong with OCR why do they hate brackets?!?!?? Screwing us over for no reason we basically have to guess what they mean which doesn't test what we know.

-3m is right. Isnt it?

Reply 782

♥Samantha♥

19

I forgot 180 degrees in that sine question fcccckkkkkk

Reply 783

JoshP97

1

Original post by Mr Moon Man

How did you get that?

You are asked to find the Sum of a series Un between U2 and U4

you are told that the next term in a series is:

(remainder of the previous term when divided by 3) x 5

i) U1 = a = 5, so:

Sum from 2 to 4 = U2 + U3 + U4 = 10 + 5 + 10 = 25

ii) U1 = a = 6, so:

Sum for 2 to 4 = U2 + U3 + U4 = 0 + 0 + 0 = 0 (because when 6 is divided by 3 the remainder is 0 and zero times or divided by a number is 0 so all terms after U1, will be zero.

Reply 784

♥Samantha♥

19

After the exam I thought it's gone really well but now I'm realising all these stupid mistakes.

Reply 785

Rubato

14

Original post by OGGUS

I think I got a like 50%. :angry:

Worst exam ever

I don't think I even got 50% and I'm retaking lol!

I didn't understand any of the section B questions.

Reply 786

Shipreck

14

Original post by ♥Samantha♥

What are you serious with that log question? I put -3m! Wtf is wrong with OCR why do they hate brackets?!?!?? Screwing us over for no reason we basically have to guess what they mean which doesn't test what we know.

That's the right answer

Reply 787

♥Samantha♥

19

Original post by Slenderman

-3m is right. Isnt it?

Idk people r saying its -m^3

Reply 788

Akhawais

1

Original post by Shipreck

That isn't what the question was. The question was -loga(a^m)^3 = -loga(a^3m) = -3m.

That's exactly what I've put into the calculators. You can't multiply the powers because the bracket is just defining which terms to log. The cube is for the whole loga(a^m) term. As I said, OCR are missing out brackets which has lead to this confusion but I'm fairly certain that it's -3^m

Reply 789

Mr Moon Man

11

Original post by Akhawais

That's exactly what I've put into the calculators. You can't multiply the powers because the bracket is just defining which terms to log. The cube is for the whole loga(a^m) term. As I said, OCR are missing out brackets which has lead to this confusion but I'm fairly certain that it's -3^m

There was a question exactly like this a few years back and based on the answer to that older question it should be -3m

Reply 790

Mr Moon Man

11

Original post by Mr Moon Man

There was a question exactly like this a few years back and based on the answer to that older question it should be -3m

http://www.mei.org.uk/files/papers/2012_Jan_c2.pdf

Question 4

Reply 791

Akhawais

1

Original post by Mr Moon Man

http://www.mei.org.uk/files/papers/2012_Jan_c2.pdf

Question 4

Yeah I guess. Like I said, OCR need to use brackets. You can see in part i and iii that there are no brackets around the term which is confusing.

Reply 792

ant1greeny

Can anyone remember exactly what the question with the f(x) and h stuff was?

And were you meant to find the value of h or just simplify the equation?

Reply 793

tizzaclaire98

12

Can someone explain why I only got two values? thanks :smile:

Reply 794

Mr Moon Man

11

Original post by tizzaclaire98

Can someone explain why I only got two values? thanks :smile:

Sin(X)=0 for 0,180, and 360

Reply 795

Studious_Student

10

What was the value of theta for the sector question again? I remember somewhat that the radius was 12

Reply 796

Jowen12

2

Original post by tizzaclaire98

Can someone explain why I only got two values? thanks :smile:

If you were to factorise out the sin y, you would get sin y = 1/4 OR 0

You've found the values for 1/4 but missed the values for if sin were 0 (0, 180 and 360)

Reply 797

Mr Moon Man

11

Original post by ant1greeny

Can anyone remember exactly what the question with the f(x) and h stuff was?

And were you meant to find the value of h or just simplify the equation?

You were meant to simplify it

Reply 798

Jowen12

2

Original post by Studious_Student

What was the value of theta for the sector question again? I remember somewhat that the radius was 12

1.8 I believe? Probably wrong though!

Reply 799

tizzaclaire98

12

Original post by ant1greeny

Can anyone remember exactly what the question with the f(x) and h stuff was?

And were you meant to find the value of h or just simplify the equation?

Its a differentiation by first principles question.

Q:
y = x^2 - 2x
find dy/dx on the chord between x=5 and x=5.1.

A:
8.1

Q:
given that f(x) = x^2 - 2x
find (f(5+h) - f(5))/h

A:
sub 5+h for x:
(5+h)^2 - 2(5+h) = 25+10h+h^2 -10 -2h = 15 +8h +h^2
minus f(x) sub 5 for x:
15+8h+h^2 - (25-10)= 8h+h^2
Divide by h:
8 + h

Q:
gradient at x=5

A:
deltay/deltax = 8 + h
as h tends to 0, gradient tends to 8, so dy/dx = 8

[Official Thread] OCR MEI AS Mathematics 2016 (C1, C2 & S1)

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