Higher November 2019 Paper 4 Q9
9 Here is function A.
(a) A number, \(k\), is input into function A.
The output is also \(k\).
The output is also \(k\).
Find the value of \(k\). [3]
(b) The output of function A is \(y\).
Write an algebraic expression, in terms of \(y\), for the input of function A. [2]
(c) The diagram shows a composite function with an input, \(n\), and an output of 96.
Find the value of \(n\). [2]
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| 6 | 3 | B1 for \(3(k - 4) = k\) oe M1 for solving their equation to get \(k\) on one side and numbers on the other e.g. \(3k - k = 12\) | also \(\frac{k}{3} + 4 = k\) condone use of other letters |
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| \(\frac{y}{3} + 4\) oe | 2 | M1 for ÷ 3 and + 4 e.g. \(\frac{y + 4}{3}\) | |
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| 16 | 2 | B1 for output of first function as 36 or \(3(3(n - 4) - 4) = 96\) or better | e.g. \(9n - 48 = 96\) |