1/2为底数~~~~~~~
给个过程,谢谢~~~~~~~~~~~
1/2为底数~~~~~~~
给个过程,谢谢~~~~~~~~~~~
y=log1/2(x²-ax+a)
y=log1/2(x)在x>0上是减函数,所以当x²-ax+a是减函数时,y=log1/2(x²-ax+a)是增函数,
函数y=log1/2(x²-ax+a)在区间负无穷大到根号2上为增函数,则f(x)=x²-ax+a在区间负无穷大到根号2上为减函数。f(x)=(x-a/2)^2-a^2+a
x在(-无穷大,a/2]上是减函数,
所以a/2>=根号2 a>=2根号2