Cost: C^2=x^2+98*sq rt of x + 57

Revenue:890(x-4)^2+29R^2=26,100

Find the marginal cost dC/dx at x=4

1 answer

Assuming you mean
c^2 = x^2 + 98√(x+57)
then
c^2(4) = 4^2 + 98√61
= 16+98√61
c(4) = 27.95

2c dc/dx = 2x + 49/√(x+57)
at x=4, we have

55.90 dc/dx = 8+49/√61
dc/dx = 0.255

Of course, I might have misread the function, with all those pesky words instead of nice math notation ...