Try It Yourself#

Exercise 1#

Marginal revenue

The weekly demand for Math-Hero video games is given by

p=x3150x+1000

where x is the number of video games produced and sold, and p is in dollars. Using the marginal revenue function, R(x), approximate the marginal revenue when 10 Math-Hero video games have been produced and sold and interpret the result.

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Answer: $2000, revenue increases by about $2000 when weekly sales increase from 10 to 11

Exercise 2#

Marginal revenue

The weekly demand for Math Wars - Return of the Calculus video games is given by

p=250x5+3500

where x is the number thousands of video games produced and sold, and p is in dollars.

Using the marginal revenue function, R(x), approximate the marginal revenue when 10,000 video games have been produced and sold and interpret the result.

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Answer: $3450, revenue increases by about $3450 when weekly sales increase from 10,000 to 11,000

Exercise 3#

Marginal average cost

The daily cost (in dollars) of producing LCD ultra-high definition televisions is given by

C(x)=5x350x2+50x+2500

where x denotes the number of thousands of televisions produced in a day.

Using the marginal average cost function, C(x), approximate the marginal average cost when 5000 televisions have been produced and interpret the result.

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Answer: $100, average cost decreases by about $100 when production increases from 5000 to 6000

Exercise 4#

Elasticity of demand

Given the demand equation p+x5=40, where p represents the price in dollars and x the number of units, determine the elasticity of demand when the price p is equal to $20 and interpret the result.

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Answer: E(20)=1, unitary demand and total revenue is maximized

Exercise 5#

Elasticity of demand

The demand for a product is given by

f(p)=6+7p.

Determine the elasticity when p=3 and interpret the result.

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Answer: E(3)=7/25, inelastic demand

Exercise 6#

Unitary demand

Given the demand equation p=12x225, determine the price p at which demand is unitary.

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Answer: p=8

Exercise 7#

Maximum revenue

Given the demand equation p+5x=20, determine the price p at which total revenue is maximized.

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Answer: p=10