well, finding the first six terms is easy, right?
An = 5n^2-1, so here's a table:
n An
1 5*1^2-1 = 5-1 = 4
2 5*2^2-2 = 20-2 = 18
3 5*3^2-3 = 45-3 = 42
4 5*4^2-4 = 80-4 = 76
5 5*5^2-5 = 125-5 = 120
6 5*6^2-6 = 180-6 = 174
Now just add 'em up to get S6
Please help me solve this problem?!?!
Find the first six terms and the sixth partial sum of the sequence whose nth term is
an = 5n2 − n.
a1 =
a2 =
a3 =
a4 =
a5 =
a6 =
S6 =
1 answer