Solution

ID: past-exam-of-the-mathematics-course-of-the-year-1-of-the-natural-sciences-course-of-the-university-of-cambridge/2019/paper-2/17/c/ii/solution

Successive substitution in the matrix recurrence relation gives . In the matrix power of , every adjacent cancels, so . Consequently
Here for , and . The formula also gives correctly at .

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