1. ## sequences

Determine t3,t7, and tn for the arithmetic sequences with properties below

A) a=2x and d=5x

B) t14=46 and t19=100

Also, how would i create a spreadsheet file and graph for the sequence in B)

Thank you

2. Originally Posted by euclid2
Determine t3,t7, and tn for the arithmetic sequences with properties below

A) a=2x and d=5x
The general term of an arithmatic progressions is:

$\displaystyle t_n=a+d \times n$

(assuming the zeroth term is $\displaystyle a$).

So:

$\displaystyle t_3=a+d \times 3$

and

$\displaystyle t_3=a+d \times 7$

Now just replace $\displaystyle a$ and $\displaystyle d$ with the given expressions and simplify.

RonL

3. Originally Posted by CaptainBlack
The general term of an arithmatic progressions is:

$\displaystyle t_n=a+d \times n$

(assuming the zeroth term is $\displaystyle a$).

So:

$\displaystyle t_3=a+d \times 3$

and

$\displaystyle t_3=a+d \times 7$

Now just replace $\displaystyle a$ and $\displaystyle d$ with the given expressions and simplify.

RonL
It's actually $\displaystyle t_n = a + (n-1)d$ since $\displaystyle a=t_1$.

So $\displaystyle t_3 = a + 2d$ and $\displaystyle t_7 = a + 6d$.

But yes, then substitute a and d.