Question

Help please! will give medal!

Answer 1

write an explicit formula for each sequence. 4, 1.5,-1,-3.5...

Answer 2

@jim_thompson5910 @ZeHanz @phi

Answer 3

@zepdrix

Answer 4

Hmmm it looks like it's decreasing by the same amount each time. What amount is that? c:

Answer 5

i dont know what u mean

Answer 6

can u explain little more

Answer 7

@zepdrix ??

Answer 8

The first number is 4,
the next number in the sequence is 1.5.
4-1.5 = 2.5

Hmm then the next number is -1.
1.5-(-1)= 2.5

See how each number in the sequence is 2.5 less than the one before it?

Answer 9

oh ok yeah i do

Answer 10

how do i write an explicit formula

Answer 11

Hmm, the `n`th term of an arithmetic sequence is given by,\[\large a_n=a_1+(n-1)d\]
\(\large a_1\) is our first term in the sequence, 4.

\(\large d\) represents the common difference between each successive term. We determined this to be 2.5.

So just plug in the pieces.

Unless they wanted you to write this as a sum or something.. Hmm the directions don't seem very clear D:

Answer 12

no they wanted formula.. that sounds good.. thanks soo much!

Answer 13

yay c:

Answer 14

d = -2.5 @zepdrix

Answer 15

Ah sorry bout that :3

Answer 16

i just caught that @raden

Answer 17

thank you!

Answer 18

it's okay ;)