SOLUTION: A 8 ft thick slice is cut off the top of a cube, resulting in a rectangular box that has volume of 136 ft^3 . Use a graphing calculator to find the side length of the original cube

Algebra ->  Volume -> SOLUTION: A 8 ft thick slice is cut off the top of a cube, resulting in a rectangular box that has volume of 136 ft^3 . Use a graphing calculator to find the side length of the original cube      Log On


   

Question 704378: A 8 ft thick slice is cut off the top of a cube, resulting in a rectangular box that has volume of 136 ft^3 . Use a graphing calculator to find the side length of the original cube. Round your answer to two decimal places.
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
A 8 ft thick slice is cut off the top of a cube, resulting in a rectangular box that has volume of 136 ft^3.
:
Let x = the side of the cube
then
x^3 = original vol of the cube
and
8x^2 = vol of the 8 ft slice
:
Therefore:
x^3 - 8x^2 = 136
x^3 - 8x^2 - 136 = 0
:
In your graphing calc looks like
+graph%28+300%2C+200%2C+-6%2C+20%2C+-500%2C+1000%2C+x%5E3-8x%5E2-136%29+
Using the calc "zero" feature x = 9.5052584 ~ 9.51, original side length