(理科)已知函數(shù)f(x)=alnx-ax-3(a∈R).
(1)討論函數(shù)f(x)的單調(diào)性;
(2)若函數(shù)y=f(x)的圖象在點(2,f(2))處的切線的傾斜角為45°,對任意的t∈[1,2],若函數(shù)
g(x)=x3+x2[f/(x)+]在區(qū)間(t,3)上有最值,求實數(shù)m取值范圍;
(3)求證:ln(2
2+1)+ln(3
2+1)+ln(4
2+1)+…+ln(n
2+1)<1+2lnn!(n≥2,n∈N
*)
(文科) 已知函數(shù)
f(x)=ax3+x2-2x+c(1)若x=-1是f(x)的極值點且f(x)的圖象過原點,求f(x)的極值;
(2)若
g(x)=bx2-x+d,在(1)的條件下,是否存在實數(shù)b,使得函數(shù)g(x)的圖象與函數(shù)f(x)的圖象恒有含x=-1的三個不同交點?若存在,求出實數(shù)b的取值范圍;否則說明理由.