Q. If Un of the sequence 2, 4, 8,... is 512, find n.
Eq.: Un = ar^n-1
Attempt:
Un = ar^n-1
2.2^n-1 = 512
n = 9
My question is, can n be solved without randomly subbing values into n? Thank you.
Apologies if I was unclear. I understand why n = 9, i.e. 2^9 = 512. What I meant was whether or not 9, itself, can be calculated from just:
2.2^n-1 = 512
I don't believe it's possible but just wanted to double check with you guys. Thanks again.