1. The profit function for a compnay is(adsbygoogle = window.adsbygoogle || []).push({});

P(x)=-390+24x+5x^2-(1/3)x^3, where x represents the demand for the product(doghouse). Find the approximate change in profit for a 1-unit change in demand when the demand is at a level of 1000 doghouses. Use the differential.

-my answer that i got is -$989976

am i correct? can profit be negative?

2. An oil slick is in the shape of a circle. Find the approximate increase in the area of the slick if tis radisu increases form 1.2 miles to 1.4miles.

-my answer is 0.48pi miles^2

am i correct?

and one more question, when would you use differentials and when would you use linear approximation?

Thanks for your time.

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# Homework Help: Profit function and differentials

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