函数y=根号下mx平方-6mx+m+8的定义域为R,求m范围.

问题描述:

函数y=根号下mx平方-6mx+m+8的定义域为R,求m范围.

y=√(mx²-6mx+m+8)的定义域为R
当m=0时√8=2√2>0满足题意
当m>0,△=36m²-4m(m+8)解得0所以m范围[0,1]