f(x)= log(a (x+1) ) = (1/ln a) ln (x+1) , 必须 x+1>0, 就是x>-1
g(x)=log(a (1-x) ) = (1/ln a) ln (1-x), 必须 1-x>0, 就是 x 0, 则
(d/dx)(f(x)+g(x)) >0 x0 时 f(x)+g(x) decreasing
x
f(x)= log(a (x+1) ) = (1/ln a) ln (x+1) , 必须 x+1>0, 就是x>-1
g(x)=log(a (1-x) ) = (1/ln a) ln (1-x), 必须 1-x>0, 就是 x 0, 则
(d/dx)(f(x)+g(x)) >0 x0 时 f(x)+g(x) decreasing
x