若f(x)=x+ln(x-5),g(x)=ln(x-1),解不等式f'(x)>g'(x) 麻烦过程详细点谢谢
问题描述:
若f(x)=x+ln(x-5),g(x)=ln(x-1),解不等式f'(x)>g'(x) 麻烦过程详细点谢谢
答
f`(X)=1+1/(X-5)=(x-4)/(x-5) G`(X)=1/(x-1)
因为真数大于零
答
f'(x)=1+1/(x-5)=(x-4)/(x-5)
g'(x)=1/(x-1)
(x-4)/(x-5)-1/(x-1)>0
(x²-5x+4-x+5)/(x-5)(x-1)>0
(x-3)²/(x-5)(x-1)>0
分分子大于0
则(x-5)(x-1)>0
x5
对数的真数大于0
所以x>5