Explanation:
a. The profit function, P(x), can be found by subtracting the cost function from the revenue function.
P(x) = R(x) - C(x)
P(x) = (-0.04x² + 320x) - (85x + 120,000)
P(x) = -0.04x² + 235x - 120,000
b. To find the profit if 1000 bicycles are produced and sold, substitute x=1000 into the profit function:
P(1000) = -0.04(1000)² + 235(1000) - 120,000
P(1000) = -40,000 + 235,000 - 120,000
P(1000) = 75,000
So, the profit would be $75,000 if 1000 bicycles are produced and sold.
c. To find the break-even point, we set the profit function equal to zero and solve for x:
P(x) = 0
-0.04x² + 235x - 120,000 = 0
Using the quadratic formula or factoring, we can find that the break-even point occurs when:
x = (235 +/- sqrt(235^2 - 4(-0.04)(-120,000)))/(2(-0.04))
x = (235 +/- sqrt(55,089,000))/(-0.08)
x = (235 +/- 7,500)/(-0.08)
x = (235 - 7,500)/(-0.08) or (235 + 7,500)/(-0.08)
x = -31,250/ -0.08 or 5,375/-0.08
x = 3906.25 or -64,375
Since negative values of x do not make sense in this context, the break-even point occurs when 3906.25 bicycles are produced and sold.