Find the first order derivative of y= 5L - L³/6

To find the first order derivative of the given function y= 5L - L³/6, we need to differentiate with respect to L.

dy/dL = d/dL (5L) - d/dL (L³/6)
dy/dL = 5 - 3L²/6
dy/dL = 5 - L²/2

Therefore, the first order derivative of y= 5L - L³/6 is dy/dL = 5 - L²/2.