求学霸们帮忙解答一下,这道题目该怎么做?希望有过程哦。谢谢!
问题描述:
答
Y=[2(X²-9)+18]/(X-3) =2(X+3)+18/(X-3) =2(X-3)+18/(X-3)+12 ≥2√[2(X-3)×18/(X-3)]+12 =12+12 =24. ∴值域:[24,+∞). 采纳吧,谢啦!
Y=[2(X²-9)+18]/(X-3) =2(X+3)+18/(X-3) =2(X-3)+18/(X-3)+12 ≥2√[2(X-3)×18/(X-3)]+12 =12+12 =24. ∴值域:[24,+∞). 采纳吧,谢啦!