A box without a lid is constructed from a 38 inch by 38 inch piece of cardboard by cutting in. squares from each corner and folding up the sides.

a) Determine the volume of the box as a function of the variable .
b) Use a graphing calculator to approximate the values of that produce a volume of 3858.1875.
c)There are 3 values of that produce the given value but only two of them are acceptable in the context of the problem. List the two answers, to at least one decimal place.
*I don't even know how to start please help!

6 answers

length of box = 38 - 2x
width of box = 38-2x
volume of box = V = (38-2x)(38-2x)(x)
V = (1444-152x+4x^2)x
V = 1444x -152x^2 +4x^3
that should get you started
SO would I set both (1444-152x+4x^2)x
and 1444x -152x^2 +4x^3 equal to 3858.1875 to find part c?
6x2 - 21xy + 8xz - 28yz.
had this same probem for college pre-calculue couldn't solve B any other way but guess and check/logic x=4.5
secondary largest possible answre is
Answer: x⋅(38-2⋅x)2
Answer: 8.06181572077
x values sould be 4.75 and 8.06........
so your answers are 4.8 and 8.1