y'=4x+3
令y'=0,得x=-3/4
1.f(-5)=30,f(-3)=4
故最大值为30,最小值为4,值域为[4,30]
2.f(-3/4)=-49/8,f(-3)=4,f(3)=22
故最大值为22,最小值为-49/8,值域为[-49/8,22]
y'=4x+3
令y'=0,得x=-3/4
1.f(-5)=30,f(-3)=4
故最大值为30,最小值为4,值域为[4,30]
2.f(-3/4)=-49/8,f(-3)=4,f(3)=22
故最大值为22,最小值为-49/8,值域为[-49/8,22]