The diagram shows the circle with equation (x – 2)² + y² = 8. The chord AB of the circle intersects the positive y-axis at A and is parallel to the x-axis. [Figure 8.1]
- (a)Find, by calculation, the coordinates of A and B.[3]
- (b)Find the volume of revolution when the shaded segment, bounded by the circle and the chord AB, is rotated through 360° about the x-axis.[5]
This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.
Mark scheme
Marking points from the official mark scheme (Feb/Mar 2022). The mark or mark type is shown in brackets.
- [B1] (-2)² + y² = 8 leading to y = 2 leading to A = (0,2)
- [M1] Substitute y = their 2 into circle leading to (x - 2)² + 4 = 8
- [A1] B = (4, 2)
- [*M1] Attempt to find [π]∫(8-(x-2)²)dx
- [A1] [π][8x-(x-2)³/3] or [π][8x-(x³/3-2x²+4x)]
- [DM1] [π][(32-16/3)] or [π][(32-(64/3-32+16))]
- [B1 FT] Volume of cylinder = π×2²×4=16π
- [A1] [Volume of revolution = 26⅔π - 16π =]10⅔π
Write your answer and get it marked
On Oracle Prep you can write or photograph your own answer and have it marked by AI against this mark scheme, with feedback on what you missed.
Sign up free →