Test for relative extrema and saddle points. $z = x ^ { 2 } - 8 x y + y ^ { 2 } + 120 x$
A)saddle point at $( - 4 , - 16 , - 720 )$
B)saddle point at $( 4,16,240 )$
C)saddle point at $( 0,0,0 )$
D)relative minimum at $( 4 , - 16,1264 )$
E)relative minimum at $( 16,128,2176 )$

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The Answer of Test for relative extrema and saddle points. $z = x ^ { 2 } - 8 x y + y ^ { 2 } + 120 x$
A)saddle point at $( - 4 , - 16 , - 720 )$
B)saddle point at $( 4,16,240 )$
C)saddle point at $( 0,0,0 )$
D)relative minimum at $( 4 , - 16,1264 )$
E)relative minimum at $( 16,128,2176 )$

Test for Relative Extrema and Saddle Points z=x2−8xy+y2+120xz = x ^ { 2 } - 8 x y + y ^ { 2 } + 120 xz=x2−8xy+y2+120x

Test for Relative Extrema and Saddle Points $z = x ^ { 2 } - 8 x y + y ^ { 2 } + 120 x$