Date | May 2019 | Marks available | 4 | Reference code | 19M.2.AHL.TZ1.H_1 |
Level | Additional Higher Level | Paper | Paper 2 | Time zone | Time zone 1 |
Command term | Find | Question number | H_1 | Adapted from | N/A |
Question
Let l be the tangent to the curve y=xe2x at the point (1, e2).
Find the coordinates of the point where l meets the x-axis.
Markscheme
* This question is from an exam for a previous syllabus, and may contain minor differences in marking or structure.
METHOD 1
equation of tangent is y=22.167…x−14.778… OR y=−7.389…=22.167…(x−1) (M1)(A1)
meets the x-axis when y=0
x=0.667
meets x-axis at (0.667, 0)(=(23,0)) A1A1
Note: Award A1 for x=23 or x=0.667 seen and A1 for coordinates (x, 0) given.
METHOD 1
Attempt to differentiate (M1)
dydx=e2x+2xe2x
when x=1, dydx=3e2 (M1)
equation of the tangent is y−e2=3e2(x−1)
y=3e2x−2e2
meets x-axis at x=23
(23,0) A1A1
Note: Award A1 for x=23 or x=0.667 seen and A1 for coordinates (x, 0) given.
[4 marks]