October 2021 Paper 2 Q1

OCR MEICurrent spec2 marksSketching & Transforming Graphs

1 The equation of a curve is \(y = 4x^2 + 8x + 1\).

The curve is stretched parallel to the \(x\)-axis with scale factor 2.

Find the equation of the new curve, giving your answer in the form \(y = ax^2 + bx + c\), where \(a\), \(b\) and \(c\) are integers to be determined. [2]

Mark scheme

Scheme	Marks	AO
\((y =)\ 4(kx)^2 + 8(kx) + 1\) soi	M1	1.1a
\(y = x^2 + 4x + 1\) isw	A1	1.1
	[2]

Notes

M1: \(k = \frac{1}{2}\); condone \(k = 2\); condone omission of brackets

A1: must see “\(y =\)” either here or in first line