Posted by Brad Paul on September 22, 2002 at 16:17:20:
In Reply to: Precal functions posted by A.C on September 22, 2002 at 15:13:22:
: I dont understand hoe to get the volume of the box in terms of x heres the hole problem.
: An open top box has a surface area of 20sq.units.The base of the box is a square of lenght of x. Express the volume of the box in terms of x.
: thank you for your help:)
What is the area of the bottom of the box in terms of x?
Abottom=x2
We do not know the height of the side of the box. But that is OK we
will just call it h and write our equations as if we knew h's value.
What is the surface area of the four sides of the box?
Ssides=4*x*h
What is the total surface ares of the open top box?
Stotal=Abottom + Ssides = x2+4*x*h
where Stotal=20 sq. units.
Now what is the volume of the box?
V=x2*h So we need to solve for h and plug it into our volume equation. I
suggest you do the algebra with just the letters then plug in the
numbers.