Edexcel C3 June 2016 - Unofficial Mark Scheme

I don't understand why it isn't just your smallest value from the previous question?

guys am I counting this right? somebody please help me we need 480 ums for an A, I has 251 from AS , that means I need 229 across C3 C4 M1 ? I think I got 55 marks in M1 , same in C3 , does that mean I need 89 ums in C4 to still get an A??? how many marks approximately is 89 ums? can I still get the A? PLEASE help
am reposting until somebody helps me

Wait. Your first post made it sound as if you differentiated the original fraction (and subbed in 3) with your calculator but didn't write any working out down.

If you differentiated the original fraction manually (quotient rule with a quartic - nasty but possible), full marks in part (b) for definite.
If you differentiated the quadratic but with A and B in place of the values 3 and 4, probably but not necessarily full marks for part (b). If you differentiate, A goes away but B does not, and you can't just retroactively work out its value from your calculator and get full credit. You might lose up to 3 marks.
If you differentiated the quadratic with 3 and 4 (regardless of where you obtained the numbers), or later replaced A and B with 3 and 4 and differentiated again, probably full marks in part (b).

How the should we know? Grade boundaries haven't been released yet. Go and look at past papers of similar difficulties to this one then look at the raw mark to ums convertor on EDEXCELs website.


Or look at a random guess someone has made for grade boundaries

Or draw your own conclusions from the C3 exam poll. The physics one had a nice bell curve but for C3 a significant amount found it hard or very hard

I don't understand why it isn't just your smallest value from the previous question?

89 UMS is around 67 ish for C4 maybe? (rough estimate)

That's correct - 89 UMS tends to vary a bit, it has been around 65 (2014), and 69 (2015 for 90 UMS, 89 didn't exist). I'd suggest 68 + in C4 should do it

WOW! idiota ! i asked for help not a lecture, i didn't say u were psychic , i asked for help, if you cnt help then don't reply , BLEH BLEH BLEH

No, i think your original understanding of what I did was right- but for the first line of my working for part b, I wrote f(x)= x^2 +3 +4/(x+2) (or whatever it was) - then i differentiated this manually and did the rest of the question as you normally would.
I know I didn't work out the values of A and B properly, but surely this part is only being assessed in part a? Since I did get the values (using a sly method, but again, this only relates to part a really), and then differentiated with numerical values of a and b, surely i'll get full? i'm hoping so anyway..

guys am I counting this right? somebody please help me we need 480 ums for an A, I has 251 from AS , that means I need 229 across C3 C4 M1 ? I think I got 55 marks in M1 , same in C3 , does that mean I need 89 ums in C4 to still get an A??? how many marks approximately is 89 ums? can I still get the A? PLEASE help
am reposting until somebody helps me

Thanks , 68+ is barely possible for me , I have no choice tho

Woah, firstly chill. Panicking is literally the worst thing you can do right now.

Yes, you need 229 UMS across C3,C4 and M1 for the A.

55/75 in M1 is approximately 75 UMS - its usually 50/51 for a B and around 59/60 for an A (however given how tricky M1 was this year, it could be lower - so you could have 77/78 us)

I haven't seen the paper yet (this one) but based off the worked solutions PDF, and how people have responded to the paper (and whatever questions my sibling told me) I would predict around 59/60 for an A, and 51/52 for a B, so 55/75 on C3 will probably net you around 73-75 UMS.

Basically for C3 and M1 you should assume an average of 75 UMS on each paper, it may be give or take a few UMS when the boundaries come out. That puts you on 150 UMS. Since its only 229 UMS you need for an A, you need 79 UMS on C4 to get an A.

Remember this is just an estimate though, your UMS will depend on the grade boundaries. So aim for as high a mark as possible on C4. So basically you need to getting 59/75 and up to realistically be hitting your C4 target.

59/75 ? not 68? some people are saying 68 marks ?

Having just done some solutions (no calculator so not done a lot of specifics and I see others have uploaded anyway so no point posting), certainly a relatively time consuming paper. Actual questions fairly standard though.

You got 251/300 in AS correct?

Because of that 11-mark buffer you got in AS, you will need approximately 59-60/75 on C4 to get 79/100 UMS.