Question

c(x) = 6x^2 + 14x + 18

a) find marginal cost function
b) the cost and marginal cost when 16 units are produced
c) cost of producing the 16th unit

Answer 1

take derivative with respect to x and set it equal to zero then solve for x

Answer 2

12x + 14 = 0
12x = -14
x = -14/12 ?

Answer 3

What is the marginal cost function? What is marginal cost?

Answer 4

The marginal cost function is the derivative of the marginal cost function. So take the derivative of c(x) \[\huge d\frac{c(x)}{dx}\]

Answer 5

c'(x)=12x+14

Answer 6

Oo ok thank you. So that is it.

How about part b? Do i just plug in 16 for x?

c'(x)=12x+14= 12(16) + 14 = 206 ???

And how would i answer part c ?

Answer 7

In part b for the cost substitute 16 for x in the cost function
then substitute 16 for x in the marginal cost function or the derivative of c(x) which you have done.

for just add the marginal coast to the cost. so
c(16)+c'(x) evaluated @ 16 is the cost of producing 16units.
\[\huge c(16)+c'(16)\]

Answer 8

I meant to write
for c just add the marginal coast to the cost. so
c(16)+c'(x) evaluated @ 16 is the cost of producing 16units.

Answer 9

Ooo ok I got thank you very very much!

Answer 10

got it*