Edexcel Mathematics October 2021 · Paper 1 · Question 3 · ExamRizz

ExamRizzEdexcel MathematicsMathematics

October 2021 · Paper 1 · Question 3 · 6 marks

3. The sequence u1, u2, u3, … is defined by un + 1 = k − 24 un u1 = 2 where k is an integer. Given that u1 + 2u2 + u3 = 0 (a) show that 3 k2 − 58k + 240 = 0 (3) (b) Find the value of k, giving a reason for your answer. (2) (c) Find the value of u3 (1) 7

Lesson: Binomial Expansion for Positive Integer n