The values of x and y are always positive, and x^2 and y vary inversely. If y is 10 when x is 2, then find x when y is 4000.
y = k/x2
x2y= k = 22 *10 = 40
x2 y = 40
x2 (4000) = 40
x2 = 1/100
x = 1/10