Question

已知函数ｆ（Ｘ）＝ａ１ｎＸ一ａＸ一３（ａ属于Ｒ）,若函数ｆ（Ｘ）的图象在Ｘ＝４处切线的斜率为３／...

Answer 1

f'(x)=a/x-a

f'(4)=a/4-a=3/2

a=-2

f(x)=-2lnx+2x-3

g(x)=x^3/3+x^2[2-2/x+m/2]

g'(x)=x^2+(4+m)x-2

根据题意

Δ=m^2+8m+16+8>0必有两个根

g'(1)=3+m

g'(3)=19+3m

若g'(1),g'(3)