Date | November 2016 | Marks available | 3 | Reference code | 16N.2.hl.TZ0.5 |
Level | HL only | Paper | 2 | Time zone | TZ0 |
Command term | Sketch | Question number | 5 | Adapted from | N/A |
Question
Consider the function f defined by f(x)=3xarccos(x) where −1⩽x⩽1.
Sketch the graph of f indicating clearly any intercepts with the axes and the coordinates of any local maximum or minimum points.
State the range of f.
Solve the inequality |3xarccos(x)|>1.
Markscheme
correct shape passing through the origin and correct domain A1
Note: Endpoint coordinates are not required. The domain can be indicated by −1 and 1 marked on the axis.
(0.652, 1.68) A1
two correct intercepts (coordinates not required) A1
Note: A graph passing through the origin is sufficient for (0, 0).
[3 marks]
[−9.42, 1.68] (or −3π, 1.68]) A1A1
Note: Award A1A0 for open or semi-open intervals with correct endpoints. Award A1A0 for closed intervals with one correct endpoint.
[2 marks]
attempting to solve either |3xarccos(x)|>1 (or equivalent) or |3xarccos(x)|=1 (or equivalent) (eg. graphically) (M1)
x=−0.189, 0.254, 0.937 (A1)
−1⩽x<−0.189 or 0.254<x<0.937 A1A1
Note: Award A0 for x<−0.189.
[4 marks]