I need help with a sequences problem. Its finding an arithmetic sequence but you have to do it from the rule. I know how to find the rule and the number just not the other way around.
Example: tn=-3n+55

Question

I need help with a sequences problem.  Its finding an arithmetic sequence but you have to do it from the rule.  I know how to find the rule and the number just not the other way around.
Example: tn=-3n+55

welshfella · Answer

to find the first term put n = 1 into the formula
-3(1) + 35 = 32

-3 is the common difference so we get 32,29,26,23 etc

anonymous · Answer

but its 55.  not 35.  and I think I got it.  d= -3    T1=55
55, 52,49,46,43
is that right?  and thank you.

welshfella · Answer

oh - sorry it will be 52, 49,46 etc

welshfella · Answer

yes you are right

anonymous · Answer

Thanks man.