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

Scroll to see replies

Hi guys. For the question which you had to firstly estimate the roots of the graph and then show that the two equations made all one equation which was a cubic and then find the exact roots. You did get 3 different roots right? I've seen on the post above that someone got x = 1 and then a weird surd however I got X = - 1 then did the polynomial division thing then got the other 2 roots as a surd using quadratic formula. Was is positive or negative 1 because looking at the image of the graph it definitely showed as X = -1 as it was all on the left hand side of the Y axis ? Thanks for any help anyone can give I am STRESSING

I got x=-1 as a root too, as (x+1) is the factor, i also got two other surds :s

Reply 161

♥Samantha♥

Original post by JoshP97

For the proof question (show that ABC is 90 degrees) what did people do? I calculated the lengths of the lines using the coordinates then did used pythag to find the length, got the same answer and since pythag on works on right angled triangles I said ABC had to be a right angle. Did other people do the same?

This is a fine method. The more typical method is finding the gradients however both methods will be accepted in the mark scheme, as it has for previous years.

Reply 162

matthewhoare

Question 11 part 3 only asked for roots of where the graphs met, didn't ask for coordinates right?? I only put x values

Mark scheme anyone?

Original post by ionic285

For the remainder theorem question did anyone get b=-2 c=7

Yupppp

Reply 165

Professor Oak

Here's an Unofficial Mark Scheme. Anyone want to create a thread with it in?

Reply 166

ionic285

Original post by Realforce

https://docs.google.com/document/d/1GrOwL3hZzhJmn8rd9IyozRJX6e6-0fAlwbaEnJkJEnw/edit#

Unofficial mark scheme linked above.

Can you all please help with question 10 and 11. The question along with the answer is all that is needed. Thank you.

The mark scheme needs tidying up its a bit of a mess

Reply 167

bethygirl

For the question about proving the angle ABC was 90 degrees. So I found the 2 gradients which came out as 2 and -1/2 I believe. Many people are saying they then went on to say how 2 times -1/2 is -1 showing its perpendicular. I didn't do this, I wrote '-1/2 is the negative recipricol of 2 therefore showing it is perpendicular hence 90 degrees' is saying negative recipricol going to get me that final mark or did I need to specifically say they times to make -1 ?

Reply 168

bethygirl

what does everybody predict they've got after looking at the unofficial mark scheme Ect ? I think 65/72 unfortunately

Reply 169

Daebakness

Q11 ii) Found the x-coordinates correctly but forgot about y-coordinates. Will I miss 1 or 2 marks? (Or more... :frown:

)

(edited 7 years ago)

Reply 170

erinls2

Can anyone remember how many marks these questions were worth:

1) question 4, the rearranging formula one
2) working out the intercepts of the lines in section A
3) tangent to circle
4) last part of last question

These are the things I think I got wrong - I rearranged the wrong way for question 4 so probably won't get any marks. I got the X coordinate right for the intersections but I forgot to work out the y coordinate - how many marks will I lose for that? For some reason my tangent is just completely wrong so I don't know if I got any marks for that. In the last part of the last question I got the X coordinates right but I didn't simplify the y coordinates fully ie. I left them as 3+-root21/2 + 3 - how many marks do you think I'll lose for that?

If those are the only things I've got wrong in the paper (I *think* they might be), do you think I can still get an A in the paper?

Reply 171

erinls2

Original post by bethygirl

what does everybody predict they've got after looking at the unofficial mark scheme Ect ? I think 65/72 unfortunately

Why's that unfortunate?!

Reply 172

bethygirl

Original post by erinls2

Why's that unfortunate?!

Because I'm really struggling with core 3 and 4, I was hoping for a really high mark to bring my grade up as I need a A/B for my uni conditions

Reply 173

bethygirl

I swear there was a question asking to find the intersection coordinates of the curve and the axes ? Or did I read this wrong ?

Reply 174

DrKillerX

Original post by bethygirl

I think it its required to show M1 x M2 = -1. However, if thats the case you will lose only one mark. I will check the marking scheme

Reply 175

DrKillerX

Original post by bethygirl

I swear there was a question asking to find the intersection coordinates of the curve and the axes ? Or did I read this wrong ?

Yes there was one.

Reply 176

Studious_Student

The only questions I seem to have messed were the last two parts of the last question. I got k < -50/8 when it should have been k <-60/8 so I guess A1/2 was wrong, so 3 marks gained for method? And for the one before that I found out the root to be 6+/- root 84 / 4, but then I stupidly divided the whole thing by 4 to get 1.5 +/- root 4, and I didn't even get the y co-ordinates, how many marks do you guys think I will have lost for that question?

Reply 177

tizzaclaire98

Q1 ii: 9^3/2

I put 27 - will i lose marks for not putting +-?

Reply 178

Olivia197

Will I lose all 4 of the marks for rearranging question 4 so that c was the subject- I can't believe I did it wrong!
Thank you :smile:

Reply 179

bethygirl

Original post by tizzaclaire98

Q1 ii: 9^3/2

I put 27 - will i lose marks for not putting +-?

I only put 27. I'm looking on past papers and the ones I've looked at they've only put the positive answer in the mark scheme ?

for example :

Jan 13 - (81)^3/4 the answer is 27 only
Jan 12- (9)^-1/2 the answer is 1/3 only but has at the side 'allow + or -' therefore I presume just having 27 is completely correct :smile: