4MA0 Higher June 2011 Paper 4 Q19

EdexcelHigherOld spec3 marksAdvanced Trigonometry

19 The diagram shows triangle \(ABC\).

Triangle ABC with angle BCA = 28 degrees, angle CAB = 134 degrees and BC = 10.2 cm

Diagram NOT accurately drawn

Angle \(BCA = 28^\circ\)
Angle \(CAB = 134^\circ\)
\(BC\) =10.2 cm.

Calculate the length of \(AB\).
Give your answer correct to 3 significant figures.

(3)

Mark scheme

Scheme	Marks
\(\dfrac{AB}{\sin 28} = \dfrac{10.2}{\sin 134}\)	M1
(\(AB\) =) \(\sin 28 \times \dfrac{10.2}{\sin 134}\)	M1
6.66	A1
	(Total 3 marks)

Notes

M1: isolate \(AB\) correctly (14.17 or 14.18 or 14.2 for \(\frac{10.2}{\sin 134}\))

A1: (6.65695....) awrt 6.66

Apart from questions 5b, 8, 15d, 20b, 21b, 23, 24b (where the mark scheme states otherwise) the correct answer, unless clearly obtained by an incorrect method, should be taken to imply correct working.