a+b=10≥2(ab)^(1/2)
ab≤25
2x^2-3x-2=0
(2x+1)(x-2)=0
x=-1/2,x=2
所以cosC=-1/2
sinc=3^(1/2)/2
S△ABC=absinc/2≤25*3^(1/2)/2/2
=(25/4)*3^(1/2)
最大值为(25/4)*3^(1/2)
a+b=10≥2(ab)^(1/2)
ab≤25
2x^2-3x-2=0
(2x+1)(x-2)=0
x=-1/2,x=2
所以cosC=-1/2
sinc=3^(1/2)/2
S△ABC=absinc/2≤25*3^(1/2)/2/2
=(25/4)*3^(1/2)
最大值为(25/4)*3^(1/2)