Date | November 2020 | Marks available | 5 | Reference code | 20N.1.SL.TZ0.S_3 |
Level | Standard Level | Paper | Paper 1 (without calculator) | Time zone | Time zone 0 |
Command term | Find | Question number | S_3 | Adapted from | N/A |
Question
Let f(x)=√12-2x, x≤a. The following diagram shows part of the graph of f.
The shaded region is enclosed by the graph of f, the x-axis and the y-axis.
The graph of f intersects the x-axis at the point (a, 0).
Find the value of a.
Find the volume of the solid formed when the shaded region is revolved 360° about the x-axis.
Markscheme
* This question is from an exam for a previous syllabus, and may contain minor differences in marking or structure.
recognize f(x)=0 (M1)
eg √12-2x=0, 2x=12
a=6 (accept x=6, (6, 0)) A1 N2
[2 marks]
attempt to substitute either their limits or the function into volume formula (must involve f ) (M1)
eg
correct integration of each term A1 A1
eg
substituting limits into their integrated function and subtracting (in any order) (M1)
eg
Note: Award M0 if candidate has substituted into or .
volume A1 N2
[5 marks]