please help?????

[mathhelp1a]

Sand is falling off a coveyor onto a conical pile at a rate of 15 cubic feet per minutes? The diameter of the base of the cone is approximately twice the altitude. At what rate is the height of the pile changing when it is 10 feet high?

i got the answer 3/ 20 PIE ft/min

is that the answer correct?????

 

[BigGlenntheHeavy]

Yes, it is.

 

[mathhelp1a]

i have another problem

differentiate and simplify as indicated

y= 3/ sqrt x^2

is it -3x / x^2

is that right