Edexcel Core 3 - 21st June 2016 AM

@13 1 20 8 42 Btw, on part c of question 11:
https://a086a5a2f39bda93734c56a63fab1d7be0a9ba38.googledrive.com/host/0B1ZiqBksUHNYQXE5T2xiNDBRd2s/June%202015%20(IAL)%20QP%20-%20C34%20Edexcel.pdf

How do we know when to "stop" when doing sin^-1(10/3root(41))? are we meant to sub in 0 and 12 (since those are the limits for t) into pi(t)/6 to get the domain?

Yes to get 2pi and 0.

Reply 581

oShahpo

20

Original post by Zacken

If anybody needs any urgent help, feel free to tag me and I'll respond as soon as I can.

Hey Zack, when differentiating, do we need to show the substitutions (u and v) or can we just differentiate it and still get full marks?

Reply 582

Don Pedro K.

9

Original post by 1 8 13 20 42

Can you link the mark scheme? I loathe these questions and can't be bothered to do the earlier parts myself..

ahaha sure, here :smile:

https://07a69ccf283966549a9350d1a66951a7bc96e2dc.googledrive.com/host/0B1ZiqBksUHNYZ0JQM1NRcmdHdXM/June%202015%20(IAL)%20MS%20-%20C34%20Edexcel.pdf

Reply 583

minjinoor

10

guys, what exactly do you say to prove there's a root - is proof + 'change of sign between continuous interval' enough?

also, do we need to know what the sec cot cosec graphs are like??? i'd hate to have to transform them :s-smilie:

Reply 584

cookiemonster15

17

I swear to god, however many times I try to do june 2013, it always, always screws me over.

That paper is evil.

Reply 585

cookiemonster15

17

Ok, this is stupid, why are my posts sending twice -_-

Reply 586

Sammy9898

16

is there a 2016 jan IAL C3 paper available? if so, does anyone have it please? thanks! :smile:

Reply 587

math42

20

Original post by Don Pedro K.

ahaha sure, here :smile:

https://07a69ccf283966549a9350d1a66951a7bc96e2dc.googledrive.com/host/0B1ZiqBksUHNYZ0JQM1NRcmdHdXM/June%202015%20(IAL)%20MS%20-%20C34%20Edexcel.pdf

Thanks, though I assume what the other guy said is sufficient?

Reply 588

Kevin De Bruyne

21

Original post by cookiemonster15

Ok, this is stupid, why are my posts sending twice -_-

It was a very difficult paper and I would say it doesn't matter if you don't do well in that past paper, particularly.

Original post by minjinoor

guys, what exactly do you say to prove there's a root - is proof + 'change of sign between continuous interval' enough?

also, do we need to know what the sec cot cosec graphs are like??? i'd hate to have to transform them :s-smilie:

With questions like that, best to consult mark schemes. I would tell you but I can't remember :lol :hide:

For inverse graphs, use your calculator to derive points, or just memorise the shape of the graphs. I'm sure it could come up but not sure about the likeliness.

Eg arcsin(0) is where sin is 0, but with these inverse functions you only consider them over a range where they are actual functions (i.e 1 to 1 mapping) so pick some value. You'd also have to find arcsin(1) and arcsin(-1) and make up the shape inbetween.

Reply 589

npstudent

7

What does it mean in domain/range questions when they give you a graph and they ask what is ff(0)? I get so confused because there's no function given?

Reply 590

Don Pedro K.

9

Original post by 1 8 13 20 42

Thanks, though I assume what the other guy said is sufficient?

Yep, thank you ^_^

Reply 591

Kevin De Bruyne

21

Original post by npstudent

What does it mean in domain/range questions when they give you a graph and they ask what is ff(0)? I get so confused because there's no function given?

It is definitely, 100% answerable unless an examiner has done a boo boo.

Usually you'll have the point (0,something) on the graph and then that same (something, something else) so you know that f(0) is something and f(f(0)) = f(something) = something else.

More generally, if you're asked to find ff(x) and we have that f(x) = a, then on the graph you'll have (x,a) and (a,f(a)) so you put in x first, get out a, can put in a and get out f(a) which is ff(x).

(edited 7 years ago)

Reply 592

Don Pedro K.

9

Original post by npstudent

What does it mean in domain/range questions when they give you a graph and they ask what is ff(0)? I get so confused because there's no function given?

Can you give a specific example?

Reply 593

splashywill

17

Original post by npstudent

What does it mean in domain/range questions when they give you a graph and they ask what is ff(0)? I get so confused because there's no function given?

I know the exact question you're talking about, you've got to sub 0 into the graph, It'll return a value of f(0) then sub that value into f again and i think it returns 2 more values?

Got to use your initiative!!

Reply 594

candol

7

Original post by npstudent

What does it mean in domain/range questions when they give you a graph and they ask what is ff(0)? I get so confused because there's no function given?

Its a composite function
Work out f(0) ie let x = 0 and find the y value on the graph
Then take that answer and use that as your new x value and apply your function again to generate a second y value
That should then be your final answer