1.A Bicycles manufacturer estimates that it can price its bicycles at P=140-0.02x dollars each.(adsbygoogle = window.adsbygoogle || []).push({});

where x is number sold. the cost of producing x bicycles is 900-0.01x^2 dollars. Determine the marginal profit when 20 bicycles are made.

Answer is $59.60

Similarly

2.A rocket is launched straight up. there is an observation stations 7miles from the launching site.a what rate distance between the rocket and station increasing when when rocket is 24 miles high and traveling at 200 miles per hour?

answer is 1920 miles per hour.

Note: it is not homework problems!!

just my book exercise:

I try is hardly but i cant solve please help me.

thanks a lot

I following all this but answer coming wrong

revenue = (number sold)(price)

profit = revenue - cost

marginal profit is the derivative of the profit function.

2. let y = height of the rocket , r = distance between the rocket and the station

y^2 + 7^2 = r^2

take the derivative of the above equation w/r to time , then sub in your given/calculated values to determine frac{dr}{dt}

y = 24 miles and \frac{dy}{dt} = 200 mph

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