In triangle ABCABCABC, side AB AB\,AB has length 5 cm, side BC BC\,BC has length 9 cm and side AC AC\,AC has length 7 cm.
Find the cosine of angle ACBACBACB, giving your answer as a fraction in its simplest form.
Find the exact area of the triangle.
84 exam-style questions on CCEA A Level Maths 1.4 Trigonometry, covering 1.4.1 Trigonometry, 1.4.2 Trigonometry, 1.4.3 Trigonometry, 1.4.4 Trigonometry, 1.4.5 Trigonometry, 1.4.6 Trigonometry, and 1.4 Trigonometry. Each one has a worked solution and a mark scheme showing where the marks go.