Answer:
350 the number of pretzels that must be sold to maximize profit.
Explanation:
P(x) = -0.002x2 + 1.4x - 400
Differentiating P(x) with respect to dx:
[tex]P(x)'=\frac{d(-0.002x2 + 1.4x - 400)}{dx}[/tex]
[tex]P(x)'=-2\times 0.002x+1.4[/tex]
Putting , P(x)' =0
[tex]0=-0.004x+1.4[/tex]
[tex]x=\frac{1.4}{0.004}=350[/tex]
we get , x = 350
Differentiating P(x)' with respect to dx:
[tex]P(x)''=-0.004[/tex]
P(x)''<0 (maxima)
350 the number of pretzels that must be sold to maximize profit.
