Answer:
in order to minimize net cost, the firm needs to remove 2.5 pounds of x (reduction in sulfur) and 1 pound of y ( reduction in lead) each day
Explanation:
Given that;
[tex]C(x, y)= 4000+100x^2+50y^2[/tex]
Subsidiary = 500x + 100y
The Net cost C will be:
[tex]C = 4000+100x^2+50y^2 - (500x + 100 y)[/tex]
For Critical point [tex]C_X[/tex] ; by differentiating with respect to x alone;
[tex]C_X =0+100(2x)+0 - 500 - 0[/tex]
[tex]C_X =200x - 500[/tex]
For Critical point [tex]C_Y[/tex] ; by differentiating with respect to y alone;
[tex]C_Y = 0+0+50(2y) - 0-100[/tex]
[tex]C_Y =100 y -100[/tex]
For minimum cost [tex]C_X[/tex]= 0
200x - 500 = 0
200x = 500
x = 500/2
x = 5/2
x = 2.5
For minimum cost [tex]C_Y[/tex] = 0
100y - 100 = 0
100 y = 100
y = 1
Hence; in order to minimize net cost, the firm needs to remove 2.5 pounds of x (reduction in sulfur) and 1 pound of y ( reduction in lead) each day