f(s,t)=6t²+3s²-4st-8t+6s+5
partial_f / partial_s = 6s-4t+6;
partial_f / partial_t = 12t-4s-8;
令partial_f / partial_s = 0 且partial_f / partial_t = 0有
s=-5/7,t=3/7
f_min=f(-5/7,3/7)=106/49
f(s,t)=6t²+3s²-4st-8t+6s+5
partial_f / partial_s = 6s-4t+6;
partial_f / partial_t = 12t-4s-8;
令partial_f / partial_s = 0 且partial_f / partial_t = 0有
s=-5/7,t=3/7
f_min=f(-5/7,3/7)=106/49