Posted by Casey on .
Suppose the revenue from producing and selling x units of a given product is given by R(x)=10x0.02x^2
a) Find the number of units produced if the revenue is $800.
I really need help with this, I don't know what to do?

Calculus 
Reiny,
just set R(x) = 800
800 = 10x  .02x^2
.02x^2  10x + 800 = 0
using the quad formula
x = (10 ± √36)/.04 , ahhh it would have factored
= (10 ± 6)/.04
= 400 or 100 units 
Calculus 
Casey,
The answer that I have to this question is 1000 units, I am confused.

Calculus 
Reiny,
sub in your answer
R(1000) = 10(1000)  .02(1000)^2 = 10 000
my answers
R(400) = 10(400)  .02(400)^2 = 800
R(100) = 10(100)  .02(100)^2 = 800
Why are you confused?
how did you possible get 1000? 
Calculus 
Casey,
I know I am getting the answer as you did, but the solution that I have with the question that says 1000