AQA MM1B and MPC3 exams January 23 2013

The H

Mechanics and Core 3, how do we feel about these exams?

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Reply 1

Kanda

Has anyone got the AQA M1 Jun 2012 Paper

Reply 2

KING2011BOB

To sum up the core3

Prove a (sum) = cosec^2(x)

Then use that

To say cosec^2(x) - cosecx - 3 - 0

Doesn't factorise,so then use the formula

Get cosecx values from formula

Do 1/answers to get sinx

Then do sin^-1(1/answers) to get x values,then do 180-(answers) +-360

In other words a whole world of hell in some questions!

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The last question literally I have no idea how to finish:

From integral between x and y of sec^4 (x) root(tanx)

u = tanx so du/dx = sec^2(x)

So therefore integral of 4 and 0 between sec^2 (x) root (u)

WTF do you do from here.....

Reply 3

2013mercs

cosec^2(x) - cosecx - 3 = 0, this didnt factorise as you pointed out, what i done was to plug the equation into my graphics calculator as a quadratic equation (x^2-x-3=0), this forced out two horrible answers of x=2.3027 and x=-1.302, then using these values as cosecx i worked my way through this question, seems wrong though!

Reply 4

kitkat19

Original post by 2013mercs

everyone got this...its right :biggrin:

Reply 5

2013mercs

Thats good, a mate of mine had me worried because he made cosec^2(x)-cosecx=3, factorised LHS to
cosecx(cosecx-1)=3, then either cosecx=3 or cosecx=4,

The very last question, i ended up with a fraction

Reply 6

bugsuper

Original post by 2013mercs

Your friend's logic doesn't work. If cosecx = 3 then his equation gives 3*2=6; if cosecx=4 then he should get 12. it's inconsistent. the correct method was quadratic formula to get, like, {1 +/- rt(13)}/2

did anyone do M1?

the last question on projectiles....
finding the horizontal component of velocity:
was it - displacement x time
(or) distance (divided by) time :/

finding the initial speed,
u find the vertical and horizontal components of velocity... and then find the magnitude
however i just realised that gives u the FINAL velecity and not the INITIAL velocity, so i'm wondering did we need to use a SUVAT equation to find U? it was 5 marks afterall :/

(edited 11 years ago)

Reply 9

OliT95

Original post by KING2011BOB

To sum up the core3

------------------------------------------------------------------------
The last question literally I have no idea how to finish:

From integral between x and y of sec^4 (x) root(tanx)

u = tanx so du/dx = sec^2(x)

So therefore integral of 4 and 0 between sec^2 (x) root (u)

WTF do you do from here.....

The integral was pie/4 and 0 btw. But then you make U in terms of sec^2x, so you square both sides so U^2 = tan^2x, then add 1 so U^2 + 1 = tan^2x + 1. With the identity it means U^2 + 1 = sec^2 so then you just subsitute in U^2 + 1.

Then it is (U^2 + 1) root U dU then from there multiply out brackets and integrate :smile:

Reply 10

The H

Dammit, just realised i made a stupid mistake on the 8 mark subsitution Q

Reply 11

AvaSofia

Didn't think it went brilliantly, knew I could have done so much better, however I did get the substitution and trig question right, so I'll take that as a positive!

Reply 12

con31773

Nailed the substitution question, but that trig question was awful. When I saw the question didn't factorize I used the quadratic formula to punch out two awful values making me think my calculation was wrong and moved on. The paper overall was pretty tricky, some pretty awkward questions.

Reply 13

The H

Original post by AvaSofia

Didn't think it went brilliantly, knew I could have done so much better, however I did get the substitution and trig question right, so I'll take that as a positive!

They happen to be the 2 questions I've just found out I made terrible mistakes on :frown:

Reply 14

Lucas96

In M1, question 7c how many marks will I lose for using r=ut+1/2at^2 to find the time instead of v=u+at?

Reply 15

ravxo

Original post by primo2gd4u

did anyone do M1?

i did

what did you get for the vector question
the last part, finding the distance?

Reply 16

ravxo

i thought M1 was alright
last question was confusing, i had to find alpha first then find V
ended up with 26.2 ms-1 and 39.1 degrees. anybody get the same?

Reply 17

Lucas96

Original post by ravxo

i thought M1 was alright
last question was confusing, i had to find alpha first then find V
ended up with 26.2 ms-1 and 39.1 degrees. anybody get the same?