Question

Help with sequences? I think it's A...

Answer 1

give the sequence i'll check it out

Answer 2

The tenth, eleventh, and twelfth terms of a sequence are shown in the table below:




Which of the following shows the first five terms of the sequence?
9, 6, 3, 0, -3

-9, -6, -3, 0, 3

6, 3, 0, -3, -5

-6, -3, 0, 3, 6

Answer 3

A or C i can't decide...

Answer 4

24-21=d

Answer 5

d=3

Answer 6

3

Answer 7

yea i got tht part...

Answer 8

21=a+27

Answer 9

-6

Answer 10

a=-6

Answer 11

you have to solve so you can decide

Answer 12

a1=-6,a2=-3,a3-0a4=3,a6=3

Answer 13

So what next?

Answer 14

keep adding the difference in the -6 will give u the first 5 terms

Answer 15

oh so you add -6?

Answer 16

-6+3=a2

Answer 17

keep repeating the sequence

Answer 18

-3

Answer 19

yes now keep repeating

Answer 20

so you subract 3 every time?

Answer 21

no we will add the difference cause the difference is positive

Answer 22

im conf..

Answer 23

D

Answer 24

a1+d=a2
a2+d=a3
and so on if u r confused use the AP formul an=a+(n-1)d
a

Answer 25

@camerondoherty i think u have got this if any doubt message me

Answer 26

look its quiet clear that d=3, now you just have to find a, i.e. the first term, and u can do it by just putting d=3 in any of the given below eqns-
a+9d = 21
a+10d= 24
a+11d= 27

and when you will put the value of d you will get a = -6
then just find the ap by adding 3to the preceeding terms
-6, -6+3, -6+2*3, -6+3*3, -6+4*3

Answer 27

Sorry about tht my mom called me for something

Answer 28

Summary:

1) This is an arithmetic sequence, because each term is 3 greater than the previous term: {21, 24, 27, and so on}. "3 greater than ... " implies ADDING 3 to each term to get the next term.

2) The formula L=A+(N-1)D applies here. A is the first term, L is the last term, N is the index (counter) indicating the 10th, 11th, 12th (etc.) term, and so on.

Substituting A=21 (for which N=10) into this formula, as well as D=3, allows us to calculate the first term (a) of the given sequence.

Answer 29

so d=3 right?

Answer 30

yes

Answer 31

hell yeah

Answer 32

wait so are e using a different formula?

Answer 33

L=A+(N-1)D

Answer 34

does d still equal 3?

Answer 35

yes this is the formula and yes d will remain the same for all the sequence

Answer 36

does a still equal -6?

Answer 37

yes

Answer 38

and what are we solving for?

Answer 39

for a given AP a and d never changes no matter what formula u use

Answer 40

are we solving for L?

Answer 41

we just wanted to calculate the sequence that we did. and that formula is same just nottion is different.

Answer 42

wait so its L=-6+(n-1)3

Answer 43

yes u can use that. just put n=1,2,3,4 and you will get your AP

Answer 44

ohhhhhh ok thank you

Answer 45

so to find the first term you put n as 1?

Answer 46

yes

Answer 47

so the first term is -6?

Answer 48

yes

Answer 49

Thank You Guys!

Answer 50

u r welcome @camerondoherty