Question

Find the explicit formula
a17=-145 and a34=-315

Answer 1

\(a_{17}=-145\) and \(a_{34}=-315\)

these points are \(34-17=\cdots\) far apart in the series
and \(-315-(-145)=\cdots\) far apart in value
the relationship between these two differences is easy to see

Answer 2

-10, so how would I find the explicit formula?

Answer 3

an=a1 times -10?

Answer 4

not quite

Answer 5

Can you repost that one more time please? It came up for 5 seconds but for some reason closed.

Answer 6

yeah i made a mistake so i scrapped it

Answer 7

Ok

Answer 8

the points are 17 apart in the series
and -170 apart in value
so the relationship between

element in series : value
17 : -170
\[\qquad\qquad\frac{17}{-170}=\frac1{10}\]

Answer 9

* \( -\frac 1{10}\)

Answer 10

Ahhh. So would it be an=a1 times -1/10?

Answer 11

how to get the 5?

Answer 12

d=(a34-a17)/(34-17)=-10;
an=a1+(-10)*(n-1);
a17-a1=16*d;

Answer 13

What do you mean by the 5?

Answer 14

if we are taking away 10 every time we move along in
the sequence how can we get values like \(-145,-315\)

Answer 15

value:element (n)
\[-10:1\]is\[-10\]

Answer 16

I just solved it.

Answer 17

That's right!

Answer 18

i don't see how you got your second line
@Farmer_Wu
and i dont understand your third,
can you explain a little bit ?

Answer 19

It is just a formula you can just remmenber it.
the third is just use the same way of the first.