Identify the extrema of the function f(x,y,z)=xyz{“version”:…

Identify the extrema of the function f(x,y,z)=xyz{“version”:”1.1″,”math”:”f(x,y,z)=xyz”} with constraint 2x+y+4z=12{“version”:”1.1″,”math”:”2x+y+4z=12″} and x>0,y>0,z>0{“version”:”1.1″,”math”:”x>0,y>0,z>0″}.   (At least one extreme point exists.)  Justify how you know the point is maximum or minimum. a.  Do not use Lagrange multipliers b.  Use Lagrange multipliers