c3 ln

http://pmt.physicsandmathstutor.com/download/Maths/A-level/C3/Papers-Edexcel/June%202007%20QP%20-%20C3%20Edexcel.pdf

q8b

no-one what to do.

i put in 20e^(-1/8 x6) but adding up everything doesn't work

Reply 1

NotNotBatman

Original post by will'o'wisp

Create equations for the first and second dose separately and add. So 1 hour after the second dose + 6 hours after the first dose.

(edited 7 years ago)

Reply 2

AspiringUnderdog

The second has only been in for one hour. The first has been in for 6 now.

Reply 3

will'o'wisp

Original post by NotNotBatman

Create equations for the first and second dose separately and add. So 1 hour after the second dose + 6 hours after the first dose.

ok

10e^(-1/8 x5) + 10e^(-1/8 x1)= 14.177

Reply 4

solC

Lol a question almost identical to this one came up in the 2016 paper....
Edexel recycling questions I see :wink:

Reply 5

NotNotBatman

Original post by will'o'wisp

ok

10e^(-1/8 x5) + 10e^(-1/8 x1)= 14.177

1 hr after the second dose is 6 hours after the first dose.

Reply 6

will'o'wisp

Original post by NotNotBatman

1 hr after the second dose is 6 hours after the first dose.

???????? i don't get it

the total time for everything is in that equation if i do one multiplying by 6 then i got 7 hours in total when there's only 6

Original post by solC

Lol a question almost identical to this one came up in the 2016 paper....
Edexel recycling questions I see :wink:

well den

Reply 7

dgkjhl

The drug is still in the blood stream so you have to add that on top of the dosage. So you get your answer from part a + 10mg as D

Reply 8

NotNotBatman

Original post by will'o'wisp

???????? i don't get it

the total time for everything is in that equation if i do one multiplying by 6 then i got 7 hours in total when there's only 6

well den

No,

x = De^{-\frac{1}{8}t}

"t hours after it has been taken" and it has been 6 hours, so replace t with 6 for the first dose.

Reply 9

will'o'wisp

Original post by NotNotBatman

No,

x = De^{-\frac{1}{8}t}

"t hours after it has been taken" and it has been 6 hours, so replace t with 6 for the first dose.

everytime

thanks

Reply 10

Mr M

Study Forum Helper

Original post by will'o'wisp

everytime

thanks

I've read a couple of posts from you this evening where you seem to be getting frustrated about not spotting things right away. You really shouldn't worry about this as you are doing everything right by working hard a long time before your final exams. Your efforts will definitely pay off in the end.

Reply 11

will'o'wisp

Original post by Mr M

[video]https://youtu.be/oHC1230OpOg[/video]

Really tho i can't tell. I did tons of work for that AS physics exam and spent over 50% of my time revising for it out of the 4 subjects i did at the time. E grade out of that. Nothing paid off for that. I wasted a whole year doing something i couldn't do. Hard work didn't pay off.

Reply 12

Notnek

Original post by will'o'wisp

Really tho i can't tell. I did tons of work for that AS physics exam and spent over 50% of my time revising for it out of the 4 subjects i did at the time. E grade out of that. Nothing paid off for that. I wasted a whole year doing something i couldn't do. Hard work didn't pay off.

If you continue to put in the same amount of effort as you are at the moment then I think it will pay off. You have the time.

But for M2 especially, you were trying past papers before knowing the basics. Once your mocks are finished, you need to spend time understanding the topics. For this I recommend watching Examsolutions videos - the tutorials, not the exam questions. I felt like you had finished topics without understanding them, which could be yours or your teacher's fault.