Higher June 2025 Paper 2R Q25

EdexcelCurrent spec3 marksGraphical Transformations

25 The graph of \(y = a\sin(x + b)^\circ + c\) for \(0 \leqslant x \leqslant 360\) is drawn on the grid below.

Graph of a sine curve for x from 0 to 360 with y from -4 to 5, maximum 4 at x = 45 and minimum -2 at x = 225, crossing the y-axis at 3

Find a suitable value for \(a\), for \(b\) and for \(c\)

(3)

Mark scheme

Scheme	Marks
\(a = 3\) \(b = 45\) \(c = 1\) OR \(a = -3\) \(b = 225\) \(c = 1\)	B1 B1 B1
	(3)
	(3 marks)

Notes

B1 B1 B1: B1 for \(a = 3\) or \(a = -3\)

B1 for \(a \gt 0\) and \(b = 45\) or for \(a \lt 0\) and \(b = 225\)
if no answer for \(a\) is seen allow this mark for \(b = 45\)

B1 for \(c = 1\)

Allow correct alternative angles for the value of \(b\), eg 45 or –315, 225 or –135