Date | November Example question | Marks available | 2 | Reference code | EXN.1.AHL.TZ0.10 |
Level | Additional Higher Level | Paper | Paper 1 | Time zone | Time zone 0 |
Command term | State and Determine | Question number | 10 | Adapted from | N/A |
Question
The production of oil (P), in barrels per day, from an oil field satisfies the differential equation dPdt=10002+t where t is measured in days from the start of production.
The production of oil at t=0 is 20,000 barrels per day.
Find ∫5010002+tdt.
State in context what this value represents.
Find an expression for P in terms of t.
Determine ∫3650P(t) dt and state what it represents.
Markscheme
* This sample question was produced by experienced DP mathematics senior examiners to aid teachers in preparing for external assessment in the new MAA course. There may be minor differences in formatting compared to formal exam papers.
1252.7…≈1250 (barrels per day) A1
[1 mark]
This is the increase (change) in P (production per day) between t=0 and t=5 (or during the first 5 days) A1
[1 mark]
METHOD 1
P=1000 ln(2+t)+c (M1)A1
c=20000-1000 ln 2≈19306.8… (M1)A1
P=1000 ln(2+t)+19300
METHOD 2
P∫20000dP=t∫010002+xdx (M1)
[P]P20000=1000[ln(2+x)]t0 A1
Note: A1 is for the correct integral, with the correct limits.
P-20000=1000(ln(2+t)-ln 2) (M1)A1
P=1000 ln(2+t2)+20000
[4 marks]
8847883≈8850000 (barrels) A1
Total production of oil in barrels in the first year (or first 365 days) A1
Note: For the final A1 “barrels”’ must be present either in the statement or as the units.
Accept any value which rounds correctly to 8850000
[2 marks]