函数f(X)=x2-2ax-3在区间(-无穷大,2)上为减函数,则a的取值范围?
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![函数f(X)=x2-2ax-3在区间(-无穷大,2)上为减函数,则a的取值范围?](/uploads/image/z/5440290-42-0.jpg?t=%E5%87%BD%E6%95%B0f%EF%BC%88X%EF%BC%89%3Dx2-2ax-3%E5%9C%A8%E5%8C%BA%E9%97%B4%EF%BC%88-%E6%97%A0%E7%A9%B7%E5%A4%A7%2C2%EF%BC%89%E4%B8%8A%E4%B8%BA%E5%87%8F%E5%87%BD%E6%95%B0%2C%E5%88%99a%E7%9A%84%E5%8F%96%E5%80%BC%E8%8C%83%E5%9B%B4%3F)
函数f(X)=x2-2ax-3在区间(-无穷大,2)上为减函数,则a的取值范围?
函数f(X)=x2-2ax-3在区间(-无穷大,2)上为减函数,则a的取值范围?
函数f(X)=x2-2ax-3在区间(-无穷大,2)上为减函数,则a的取值范围?
f(X)= X2-2ax-3=(x-a)^2-(a^2+3) 即该抛物线在最低点时X=a 由于该函数在区间(-无穷大,2)上为减函数,则其最低点时X值应该在区间(-无穷大,2)之外.因此,a>=2