B brumby_3 Jul 2008 212 2 May 17, 2010 #1 Find a simple formula which defines the nth term of a sequences whose first few terms are the same as those given: 1, -4, 9, -16 I already know the answer is -(-1)^n * n^2 But how would I show working out?

Find a simple formula which defines the nth term of a sequences whose first few terms are the same as those given: 1, -4, 9, -16 I already know the answer is -(-1)^n * n^2 But how would I show working out?

pickslides MHF Helper Sep 2008 5,237 1,625 Melbourne May 17, 2010 #2 \(\displaystyle 1, -4, 9, -16, \dots =1^2, -2^2, 3^2, -4^2, \dots =-(-1)^1\times 1^2, -(-1)^2\times 2^2, -(-1)^3\times \) \(\displaystyle 3^2, -(-1)^4\times 4^2, \dots \) Reactions: brumby_3

\(\displaystyle 1, -4, 9, -16, \dots =1^2, -2^2, 3^2, -4^2, \dots =-(-1)^1\times 1^2, -(-1)^2\times 2^2, -(-1)^3\times \) \(\displaystyle 3^2, -(-1)^4\times 4^2, \dots \)