Question

find the maximum value of the function f(xˏy)=(x+1) (y+4)−x^2−y^2. Note that fx(xˏy)=y+4−2x and fy(xˏy)=x+1−2y.

Answer 1

grad(f)=<fx,fy>=<0,0>
solve fx(x,y)=0 and fy(x,y)=0 for x,y, then plug these values into f(x,y)