Find the nth term of the arithmetic sequence where a1 = 5000 and d = -100

Question

amistre64 · Answer

do you recall the general formula for an arithmetic seq?

anonymous · Answer

an = dn + c

amistre64 · Answer

good, lets use that :)

amistre64 · Answer

$$a_n=a_1+d(n-1)$$ might be more applicable

amistre64 · Answer

$$a_{n}=5000-100(n-1)$$

amistre64 · Answer

when n=1, the first term; we get 5000

amistre64 · Answer

do you know if we start ar a1 or a0 tho?

anonymous · Answer

so wouldn't the first term equal 4900?

amistre64 · Answer

whats our first term?  a0  or a1 ?

anonymous · Answer

a1 i guess

amistre64 · Answer

then a1 = 5000 :)  a2 = 4900, a3 = 4800 etc .....

anonymous · Answer

but what would be the nth term?

amistre64 · Answer

$$a_{n}=5000-100(n-1)$$

whatever n value you want to plug in; that is what it will be

amistre64 · Answer

the nth terms IS:  5000 -100(n-1)

amistre64 · Answer

you have to realize that "nth" is not static, it can take on any value it wants.  When you determine you want the 253rd term, then n=253.  When you want the 15th term, then n=15; etc ....