The problem itself appears first to be simple: Find the directional derivative of the function f(x,y)=ln(x3+y2)f(x,y)=ln(x3+y2) at the point (1,2)(-1,2) in the direction of the vector 2,1-2,1but!!! The challenge is that some of the Z-Planet laws are different. In particular, "power rule" on Earth, ddxxn=nxn1ddxxn=nxn-1, on Z planet is "twisted" as the following:ddxxn=n2xn1ddxxn=n2xn-1(ddxconst=0ddxconst=0), andthe derivative of log function,ddxln(x)=1xddxln(x)=1x , turns into "ZP" oddness: ddxln(x)=exddxln(x)=ex .all the other rules and laws have not been changed.So, find the directional derivative of the function f(x,y)=ln(x3+y2)f(x,y)=ln(x3+y2) at the point (1,2)(-1,2) in the direction of the vector 2,1-2,1 for Z-Planet conditions: