Question

Given an exponential function for compounding interest, A(x) = P(.77)x, what is the rate of change?

Answer 1

@paki

Answer 2

To find rate we subtract the rate in this case is .77 or 77% - 1 or 100% and that would give you the rate in this case its decreasing by an 18%

Answer 3

I thought rate of change was derivative...

Answer 4

I dont know:(

Answer 5

rate of change is derivative

Answer 6

What did you get as an answer?

Answer 7

I think he thought you were looking for the interest rate

Answer 8

\[A=P(.77)^x \\ \frac{A}{P}=(.77)^x \]
P is a constant
take ln( ) of both sides

Answer 9

this will allow you to bring down that power of x

Answer 10

and then differentiate both sides

Answer 11

ok:)

Answer 12

I got 23% as an answer?!

Answer 13

wait?
does that mean you aren't looking for rate of change and you are looking for interest rate?

Answer 14

no! I think i am looking for rate of change. Why dont we just try out both?

Answer 15

−0.13%
−13%
0.23%
−23%
these are the answer choics

Answer 16

none of those are the rate of change
so you must be looking for interest rate

Answer 17

yes :)

Answer 18

@paki gave you the way to calculate the interest rate above
just do 77%-100%

Answer 19

-23?

Answer 20

@paki

Answer 21

yes 77-100 is -23

Answer 22

so 77%-100% is -23%

Answer 23

Thanks :)