Question

Medal & Fan
Which exponential function goes through the points (1, 8) and (4, 512)?

Answer 1

f(x) = 4(2)x

f(x) = 8(2)-x

f(x) = 4(4)-x

f(x) = 2(4)x

Answer 2

Let's use the form \[y=a \cdot 2^{bx}\]
to find out.
Enter in the points you have to form two equations.

Answer 3

Then solve the system of equations.

Answer 4

whats A?

Answer 5

idk yet
that is what we have to find

Answer 6

also have to find b

Answer 7

to find a and b you need to form those two equations I talked about

Answer 8

can i see your two equations?

Answer 9

Im not understanding , if we dont know A or B , how can i substitute anything into that equation?

Answer 10

you have the ordered pairs

Answer 11

or if you don't like to plug in ordered pairs and solve a system of equations

you could just take the points in enter it into your choices to see which choice has both ordered pairs on the curve

Answer 12

\[512=a \cdot 2^{b \cdot 4 } \\ 8=a \cdot 2^{b}\]
I just plugged in the ordered pairs
(1,8) and (4,512)
i have two equations in terms of two variables
i would try solving the system by substitution
you know like solve that second equation by 2^b and plug it into the first equation

Answer 13

@briannamooney you can continue that route
or since you have choices you can see which equation works for you by plugging in your ordered pairs