4MA0 Higher January 2018 Paper 4 Q21
21 The diagram shows a solid cone.
Diagram NOT accurately drawn
The cone has base diameter 6.8 cm, correct to 1 decimal place.
The cone has slant height 9.2 cm, correct to 1 decimal place.
The total surface area of the cone is \(k\pi\) cm²
Work out the lower bound for the value of \(k\).
Show your working clearly.
Give your answer correct to 3 significant figures.
(3)
| Scheme | Marks |
|---|---|
| 6.75 or 6.85 or 9.15 or 9.25 or 3.425 or 3.375 | B1 |
| \(\pi \times (6.75 \div 2)^2 + \pi \times (6.75 \div 2) \times 9.15\) | M1 |
| 42.3 | A1 |
| (3) |
Notes
M1: or (\(k\) =) \((6.75 \div 2)^2 + (6.75 \div 2) \times 9.15\)
A1: 42.27(1875)
dep on correct working