math
posted by Britney on .
The quantity demanded each month of the Sicard wristwatch is related to the unit price given by the equation below, where p is measured in dollars and x is measured in units of a thousand. To yield a maximum revenue, how many watches must be sold? (Round your answer to the nearest whole number.)
P=41/0.01X^2+1 (0(less than or equal to)x(less than or equal to)20)
? watches

revenue = quantity * price
r(x) = x*p(x)
= 41x/(0.01x^2+1)
dr/dx = (41.41x^2)/(.01x^2+1)^2
since the denominator is never 0,
max revenue occurs where
(41.41x^2) = 0
x = 10 
that wasn't right

sorry  can you show me my mistake?

idk...it jus said that it was wrong....but when i worked it out i got the same answer as you.