In: Math
Find the local maximum and minimum values and saddle point(s) of the function. If you have three-dimensional graphing software, graph the function with a domain and viewpoint that reveal all the important aspects of the function. (Enter your answers as a comma-separated list. If an answer does not exist, enter DNE.)
f(x, y) = x3 − 27xy + 27y3
critical point ( maximum ,minimum or saddle point ) of a function occur accordingly
fx ( partial differentiation with respect to x ) = 0
and fy ( partial differentiation with respect to y ) = 0
then calculate D = fxx .fyy - (fxy)2 at the point where fx = 0 and fy=0
where fxx => partially differentiate fx with respect to x
fyy => partially differentiate fy with respect to y
fxy => partially differentiate fx with respect to y
If D>0 and fxx > 0 => relative minimum
If D>0 and fxx < 0 => relative maximum
If D<0 => saddle point
If D = 0 then no conclusion can be drawn