Question

Which of the following is the function representing the graph below?
f(x) = (1/3)^x + 1

f(x) = (1/3)^x – 1

f(x) = 3x – 1

f(x) = 3x + 1

Answer 1

well, you have a noticeable increament/decrement on the x, y relationship

that means as one changes a bit, the one changes a lot

Answer 2

what does that mean?

is an exponential equation

Answer 3

Im confused.

Answer 4

now at 1/3, \(1^3 = 1, 1^{100000} = 1\)

Answer 5

so as the exponent for 1/3 changes, 1 remains 1, and changes dramatically
from 3 to 9 to 81 to 6561

Answer 6

from 1/3 to 1/6561, the latter number is much smaller of a fraction, and thus closer to 0

Answer 7

linear equations - straight lines - follow the formet y = mx +c. m is the gradient, c is where the line hits the x axis.

the line you show is clearly not linear - it is not a straight line. that eliminates c) and d).

looking at the other options, why not start by setting x to 0 and seeing what y becomes.

the solutions are:
A) +1
B) -1

anything to the power of zero = 1.

so if your curve intercepts x = 0 at +2, the answer is........?!?!

Answer 8

so, if you were to use say 1/6561 - 1
as choice b) suggests
you'd get -6560/6561
a negative number

but "y" in the graphic shows no negative numbers

so, which one do you think it's?

Answer 9

a ? idk im confused.:(

Answer 10

well, it's an exponential function

so, which choices give you an exponential function?

Answer 11

look, ignore jdoe and read what i wrote.

the answer is in there.

Answer 12

b ?

Answer 13

i got lost when you said so if your curve intercepts x = 0 at +2.

Answer 14

oh no nvm i understand that part lol sorry.,

Answer 15

(1/3)^0 + 1 = 2

(1/3)^0 - 1 = 0

does that make sense?

Answer 16

yess.

Answer 17

so how do i find the answer from that .

Answer 18

out of

(1/3)^1000 + 1 = ?

(1/3)^1000 - 1 = ?

which is positive?

Answer 19

the first one ?

Answer 20

yes

Answer 21

so, the 1st one is positive, the graphic shows only POSITIVE for "y"
it shows no negative ones
(1/3)^1000 - 1 means
^
smaller -1
than
1

so a number smaller than 1 -1, will give a negative value
but in the graphic "y" has no negative ones
so, there's only 1 option :)

Answer 22

so it is a ? the positive 1 ?

Answer 23

yes Lesha, and I hope you can see why! Well done you.

Answer 24

http://fooplot.com/#W3sidHlwZSI6MCwiZXEiOiIoMS8zKV54KzEiLCJjb2xvciI6IiMwMDAwMDAifSx7InR5cGUiOjEwMDAsIndpbmRvdyI6WyItNC4yNzk5OTk5OTk5OTk5OTkiLCI4LjcyIiwiLTAuMjQwMDAwMDAwMDAwMDAwMiIsIjcuNzYiXX1d

Answer 25

Thank you. (: . Veryy much !

Answer 26

yw

Answer 27

ii have one more graph question. can you help ?

Answer 28

sure, post in channel so we all can see it and help, and revise each other :)