Question

The cost C (in dollars) of manufacturing
x chairs at Martina's Furniture Factory is given by the function c(x)=0.4x^2-160x+34,108.
What is the minimum cost of manufacturing chairs?

Answer 1

d/dx{c(x)}=0.4*2*x-160
0.8x-160=0
x=160/0.8=200

Answer 2

200 is min since d^2/dx^2=0.8 is +ve

Answer 3

18,108 Is what they wanted but thanks

Answer 4

put x=200 in c(x)=0.4*200*200160*200+34108=18108

Answer 5

that is at x=200 c(x) is min and on any other it give more value of 18108