A total revenue function is given by R(x) = 1000(x^2 - 0.1x)^1/2 , where R(x) is the total revenue, in thousands of dollars, from the sale of x items. Find the rate at which total revenue is changing when 20 items have been sold.

Question

So far my answer is
R'(x) = 1000

Coming from R'(x) = 500 ((x^2) - 0.1x)^-.5 (2x - 0.1)

Answer 1

That is correct.