Edexcel Mathematics June 2023 · Paper 2 · Question 8 · ExamRizz

ExamRizzEdexcel MathematicsMathematics

June 2023 · Paper 2 · Question 8 · 6 marks

8. (a) Express 2 cos θ + 8 sin θ in the form R cos (θ – α) , where R and α are constants, R > 0 and 0 < α < 2π Give the exact value of R and give the value of α in radians to 3 decimal places. (3) The first three terms of an arithmetic sequence are cos x cos x + sin x cos x + 2 sin x x ≠ nπ Given that S9 represents the sum of the first 9 terms of this sequence as x varies, (b) (i) find the exact maximum value of S9 (ii) deduce the smallest positive value of x at which this maximum value of S9 occurs. (3) 19

Lesson: Definitions of Sine, Cosine and Tangent and Exact Values