What is the rate of change of the revenue when there are 1000 downloads. So far I have R'(1000) = (130 - .019(1000))e^(-.000250(1000)). How do I calculate to get the answer?

Question

anonymous · Answer

plug 1000 in for x

welshfella · Answer

you'll need a scientific calculator to do that one.

lynda.boyce · Answer

I have one, but how do I type it in?

welshfella · Answer

exactly as you've written it

lynda.boyce · Answer

I don't need to put in 2.718282 anywhere?

welshfella · Answer

no - just the e^x key

lynda.boyce · Answer

would I type in 130-.01981000e^-0.000150*1000

lynda.boyce · Answer

the answer I got was 130.00

welshfella · Answer

well you can simplify it by  doing some of it manually first 
130 - .019*1000 = 130 - 19 = 111
and the exponent of e = 0.000250*1000 = 0.25

so it boils down to

111* e^(-0.25)

try that one

welshfella · Answer

130 is incorrect

welshfella · Answer

- you didnt put the parentheses in

lynda.boyce · Answer

27.75

welshfella · Answer

try again 
i got 86.45

welshfella · Answer

dont forget the  negative and the parentheses

lynda.boyce · Answer

ok, I used a different calculator and got 86.4469

welshfella · Answer

yes  thats right