Higher January 2019 Paper 1 Q18

EdexcelHigherCurrent spec3 marksGraphical Transformations

18 The graph of \(y = \text{f}(x)\) is shown on the grid.

Grid with x from −9 to 9 and y from −9 to 5 showing a U-shaped parabola y = f(x) with minimum point (1, −4), crossing the x-axis at −1 and 3 and the y-axis at −3

(a) On the grid above, sketch the graph of \(y = \text{f}\left(\dfrac{1}{2}x\right)\) (2)

The graph of \(y = \text{f}(x + k)\) is shown on the grid below.

Grid with x from −9 to 9 and y from −9 to 5 showing a U-shaped parabola y = f(x + k) with minimum point (−2, −4), crossing the x-axis at −4 and 0

(b) Write down the value of \(k\) (1)

Mark scheme (a)

Scheme	Marks
Parabola through \((-4, 5), (-2, 0), (0, -3), (2, -4), (4, -3), (6, 0), (8, 5)\)	B2
	(2)

Notes

B2: For a parabola with minimum \((2, -4)\) through at least 5 of \((-4, 5), (-2, 0), (0, -3), (4, -3), (6, 0), (8, 5)\)
If not B2 then B1 For u-shaped parabola with minimum \((2, -4)\) or For u-shaped parabola through \((-2, 0), (6, 0)\) or For u-shaped parabola through \((-4, 5), (8, 5)\)

Scheme	Marks
3	B1
	(1)
	(3 marks)