Question

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

-20, -16, -12, -8, ...

Answer 1

an arithmetic equation is defined by the starting value and the common difference.

do you know what these are?

Answer 2

sorry, an arithmetic "sequence", not equation

Answer 3

you add four so +4 is the common difference?

Answer 4

d = a_{n+1} - a_{n} = -16 - (-20) = 4
a_{0} = first of sequence = -20

a_{n} = a_{0} + d(n-1)
d_{n} = -20 + 4(n-1)

Answer 5

correct!

Answer 6

and would starting value just be -20

Answer 7

excellent

Answer 8

can you help me with another

Answer 9

so, if you start with -20 and add 4 at each step (except the 0th step) you get this

\(a_n=a_0 +d \cdot \left(n-1\right)\) where n can be any whole number

Answer 10

Find the first six terms of the sequence.
\[a _{1}=4\]
[a _{n} = a _{n-1}+7\]
how do i do this

Answer 11

oops, n can be any natural number (that is 1, 2, 3, ...)

Answer 12

just plug in ...
so if you want to find \(a_2\) just take \(a_1\) and add 7

Answer 13

good luck!

Answer 14

thank u

Answer 15

you're welcome