Question

how would i determine a formula for an exponential function

Answer 1

You should be able to get those from its definition

Answer 2

y = e^x
?

Answer 3

what are you trying to do with exponential functions

Answer 4

well i have a problem with a table and im to find an equation

Answer 5

number one

Answer 6

oh ok so you need to fit an exponential curve to data
you can use a graphing calculator to this using exponential regression

Answer 7

its a multiple choice question i just need the equation theres a way to derive it form a table i remember my teacher taught us that i just cant remember

Answer 8

since its multiple choice just plug in the points and see which one works

function is decreasing so it must be in the form a^-x or (1/a)^x

Answer 9

so b?

Answer 10

B doesn't match the points though
x=0 --> y= 10

Answer 11

A then

Answer 12

haha, no thats an increasing function
x=1 --> y=10

Answer 13

wowo im going to fail this test is there some sort of easy way around this i get the rest of the logarthims section but this stuff involving graphs

Answer 14

look for key points like x=0 and x=1 since those are easy to plug in
plug in 0 for x for all of them and see which match the y-values
A -> 10/3
B-> 10
C ->10
D -> 10/3

So we can eliminate B and C, since in the table the y-value with x=0 is 10/3
Now plug in x=1
A ->10
D ->10/9

Therefore its D

Answer 15

oh so it s a matter or plugging in stuff?

Answer 16

yes when its multiple choice

Answer 17

well it will be now number 5 i get the answer 10^3=x is that correct becuase 10 is the common log?

Answer 18

yes except that should be a -3 right ?

Answer 19

how?

Answer 20

oh then its 1/10^3=x