Quandaries
and Queries 

Who is asking: Student Level: Secondary Question: Gasoline is stored in a tank which is a cylinder on its side. Height of fuel is "h" meters and the diameter is "d". The length is "l". I need to find the amount of gas in the tank when the height is h and also to calculate the fraction of how full it is. Also, the part I am really confused on is this one, 

Hi Jennifer, In a response to an earlier question Harley gave a procedure to find an expression for the volume of gas in the tank. He used the radius r of the tank rather than the diameter d, but you can replace d r by ^{d}/_{2} . If you construct this expression and then divide it by the volume of the tank you can rewrite the expression in terms of the variable ^{h}/_{d} . (I only checked this for the situation when h is less than ^{d}/_{2} , that is the tank is less than half full.) Let x = ^{h}/_{d} then the expression for the amount of gas in the tank is a function of x, say G(x). The second part of the problem is to estimate this function by ^{h}/_{d} , which is x, so the error function E is given by
The task is to find the value of x that maximizes this function. Penny 

