The point p(3,-1) is on f (x) = m+logax relative to the symmetrical point Q (1,-1) of the straight line X = 2.
∴- 1 = m+log 1, which means m=- 1.
Solvable a=2.
( 1)f(x)=- 1+log2x,g(x)+ 1 =- 1+log2(x+ 1)
∴g(x)=-2+log2(x+ 1)
(2)h(x)=g(x*2)-f(x)=-2+log2(x^2+ 1)+ 1-log2x=- 1+log2[(x^2+ 1)/x)
That is, h (x) =-1+log2 (x+1/x).
∵log2x monotonically increases, ∴ Only when x+ 1/x takes the minimum value, the function value is the minimum value.
For the "tick" function, the minimum value is taken when x= 1/x, and the minimum value is 2 at this time.
H(x)min=- 1+log22=0,x= 1。
2.f'(x)= 1/x-2x+ 1
Let f'(x)=0 to get -(2x 2-x- 1)/x = 0.
∴x=- 1/2 or x= 1, obviously the domain specifies x >;; 0, so there is only one zero.
-(2x^2-x- 1)/x>; 0 to get x
(1) monotonically decreasing interval [1, +∞), monotonically increasing interval (0, 1)
(2) If
If a> 1, the maximum value is obtained at x= 1. f(x)max=f( 1)=2