# Calculus: General Differentiation – #28135

Question: The cost of manufacturing x units of a product is $$C\left( x \right)=x\sqrt{2x+5}$$ , where C(x) is the cost in thousands of dollars and x is the number of units manufactured in the hundreds. At what rate is cost changing if 200 units are manufactured? What if 400 units are manufactured? How did you arrive at your conclusions?