Date | November Example questions | Marks available | 4 | Reference code | EXN.2.AHL.TZ0.12 |
Level | Additional Higher Level | Paper | Paper 2 | Time zone | Time zone 0 |
Command term | Show that | Question number | 12 | Adapted from | N/A |
Question
Consider the differential equation
The curve for has a gradient function given by
.
The curve passes through the point .
Use the substitution to show that where is an arbitrary constant.
By using the result from part (a) or otherwise, solve the differential equation and hence show that the curve has equation .
The curve has a point of inflexion at where . Determine the coordinates of this point of inflexion.
Use the differential equation to show that the points of zero gradient on the curve lie on two straight lines of the form where the values of are to be determined.
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.
M1
A1
A1
integrating the RHS, AG
[3 marks]
EITHER
attempts to find M1
(A1)
substitutes their into M1
attempts to complete the square (M1)
A1
A1
OR
attempts to find M1
A1
M1
attempts to complete the square (M1)
A1
A1
THEN
when , (or ) and so M1
substitutes for into their expression M1
A1
so AG
[9 marks]
METHOD 1
EITHER
a correct graph of (for approximately ) with a local minimum point below the -axis A2
Note: Award M1A1 for .
attempts to find the -coordinate of the local minimum point on the graph of (M1)
OR
a correct graph of (for approximately ) showing the location of the -intercept A2
Note: Award M1A1 for .
attempts to find the -intercept (M1)
THEN
A1
attempts to find (M1)
the coordinates are A1
METHOD 2
attempts implicit differentiation on to find M1
(or equivalent)
() A1
attempts to solve for where M1
A1
attempts to find (M1)
the coordinates are A1
[6 marks]
M1
attempts to solve for M1
or A1
and A1
Note: Award M1 for stating , M1 for substituting into , A1 for and A1 for and .
[4 marks]