OCR MEI C3 — Question 2

Exam BoardOCR MEI
ModuleC3 (Core Mathematics 3)
TopicProof

2
  1. Disprove the following statement: $$3 ^ { n } + 2 \text { is prime for all integers } n \geqslant 0 .$$
  2. Prove that no number of the form \(3 ^ { n }\) (where \(n\) is a positive integer) has 5 as its final digit.