Drawing & Using Graphs: WJEC GCSE Higher June 2019 Unit 1 Q2

Higher June 2019 Unit 1 Q2

WJECHigherCurrent spec4 marksDrawing & Using Graphs

2. Complete the table below.
Draw the graph of \(y = 3x^2 - 25\) for values of \(x\) between −3 and 4.
Use the graph paper below.
You must choose a suitable scale for the \(y\)-axis. [4]

\(x\)	–3	–2	–1	0	1	2	3	4
\(y = 3x^2 - 25\)	2		–22	–25	–22	–13	2	23

Graph paper with x-axis from -3 to 4 and an unscaled y-axis

Mark scheme

Scheme	Marks	Comments
−13	B1
Scale on y-axis ‘2cm square ≡ 10 units’.	B1
At least 7 correct plots and no incorrect plots.	P1	FT ‘their (−2, −13)’ AND ‘their uniform scale’ if possible. Allow ± ‘½ a small square’.
A smooth curve drawn through their plots.	C1	FT ‘their 8 plots’. (Only if an uniform scale used.) OR a curve through the 7 given plots and (−2, −13). Allow intention to pass through their plots (within 1 small square, either horizontally or vertically of the point).