Find an equation for the nth term of the arithmetic sequence.

a19 = -92, a20 = 6

Question

Find an equation for the nth term of the arithmetic sequence.

a19 = -92, a20 = 6

anonymous · Answer

@jim_thompson5910

anonymous · Answer

@phi @precal @Zarkon

anonymous · Answer

@Chooch146

reemii · Answer

what is the definition of an arithmetic sequence? type it here what you got in your book

anonymous · Answer

A sequence made by adding some value each time.

reemii · Answer

ok.
so, you have the first value $a_1$, then you add some quantity $C$.
$a_2=a_1+C$, $a_3=a_2+C = a_1 + 2C$... etc.

you can compute $C$ right now, since you have to adjacent value of the sequence. what do you get?

reemii · Answer

since $C$ is teh value you added to go from -92 to 6, $C=98$.
then, you use the formula $a_n = a_1 + (n-1)C$ and the fact that you know that $a_{20}=6$ to get $a_1$. good luck.