1- The arithmetic sequence is given (-2, 1, 4, 7, ...} a) Write a recursive formula. b) Write an explicit formula for the nth term. c) Find the sum of the first 30 terms. 2- The geometric sequence {3, 6, 12, 24, ...} is given. a) Write a recursive formula. b) Write an explicit formula for the nth term. c) Find the sum of the first 10 terms. 3- Using mathematical induction, show that 1+ 2 +3+ ... +n=n(n+1) /2 Show you work and each exercise