Question 969142
A rectangular area adjacent to a river is to be fenced in; no fence is needed on the river side.
 The enclosed area is to be 1000 square feet. 
Fencing for the side parallel to the river is $5 per linear foot, and fencing for the other two sides is $8 per linear foot; the four corner posts are $25 apiece.
:
the 4 post add $100 to the cost
 Let x be the length of one of the sides perpendicular to the river.
Let L = the length of side parallel to river
then
L*x = 1000
L = {{{1000/x}}}
:
(a) Write a function C(x) that describes the cost of the project.
C(x) = 8(2x) + 5({{{1000/x}}}) + 100
C(x) = 16x + {{{5000/x}}} + 100
(b) What is the domain of C? x > 0