The surface of a bill is given by the function
z=f(x,y)=2-0.5x^(2)-0.2y^(4)+0.1y
where x,y and z are given in miles. A hiker starts at x=-0.4,y=-0.7 and is traveling in a straight line
towards the point (1,0). If the hiker is moving at a speed of 2 miles per hour in the xy-plane, how quickly is
his elevation changing?
1. The surface of a hill is given by the function z=fy=2-0.5x-0.2y+0.1y
his elevation changing?