Higher November 2020 Paper 4 Q7
7 This graph shows part of a straight line.
(a) Show that the gradient of the line is 2.5. [1]
(b) Write down the equation of the line. [2]
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| Any correct reason e.g. two points identified e.g (−2,−6) and (2,4) or a triangle drawn on the graph and [gradient = ] e.g \(\frac{4 - -6}{2 - -2}\) (could be marked on graph) \(= \frac{10}{4} = (\frac{5}{2}\) or 2.5) oe | 1 | reason has to be fully correct condone triangle with base 1 and height 2.5 providing it is clear alternative 1: e.g. \(-6 = m(-2) + -1\) leading to \(m = (-6 + 1) \div -2 = \frac{-5}{-2} = (\frac{5}{2}\) or 2.5) alternative 2 : \(-6 = m(-2) + c\) \(4 = m(2) + c\) subtract \(-10 = m(-4)\) \(\frac{-10}{-4} = (\frac{5}{2}\) or 2.5) oe | |
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| \(y = 2.5x - 1\) | 2 | B1 for \(y = 2.5x + c\) (\(c \ne -1\)) | condone \(\frac{5}{2}\) for 2.5 |