下列各函数中,最小值为2的是()A,y=x+x分之一,B,y=sinx+sinx分分之一,x属于（0,二分之π）C,y=根号（x平方+2）分之x平方+3,D,y=x+根号x分之2－1,为什么,B不是取不到等号吗?麻烦分析一下,

下列各函数中,最小值为2的是()A,y=x+x分之一,B,y=sinx+sinx分分之一,x属于（0,二分之π）C,y=根号（x平方+2）分之x平方+3,D,y=x+根号x分之2－1,为什么,B不是取不到等号吗?麻烦分析一下,
下列各函数中,最小值为2的是()A,y=x+x分之一,B,y=sinx+sinx分分之一,x属于（0,二分之π）
C,y=根号（x平方+2）分之x平方+3,D,y=x+根号x分之2－1,为什么,B不是取不到等号吗?麻烦分析一下,

下列各函数中,最小值为2的是()A,y=x+x分之一,B,y=sinx+sinx分分之一,x属于（0,二分之π）C,y=根号（x平方+2）分之x平方+3,D,y=x+根号x分之2－1,为什么,B不是取不到等号吗?麻烦分析一下,
A的值域是(-∞,-2]∪[2,+∞)
B 0＜x＜π/2
0＜sinx＜1
所以值域是(2,+∞)
C y=(x^2+3)/√(x^2+2)=√(x^2+2)+1/√(x^2+2)
因为√(x^2+2)≥√2
所以值域是[3√2/2,+∞)
D y=x+2/√x-1=x+1/√x+1/√x-1≥3[x*(1/√x)*(1/√x)]^(1/3)-1=2
所以答案应该选D才对.

Spain's golden boy joined the Timberwolves announced
Ricky - Rubio, season
According to the Associated Press, the Spanish golden boy Ricky - Rubio in Barcelona held a news conference on Frid...

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Spain's golden boy joined the Timberwolves announced
Ricky - Rubio, season
According to the Associated Press, the Spanish golden boy Ricky - Rubio in Barcelona held a news conference on Friday, will be officially announced their next season to join the Minnesota Timberwolves news. The young age of just 20 players following two years of consideration, finally chose to join NBA, "I finally decided to begin my NBA journey."
"This is my dream, and that i wish to achieve this dream," he said,wholesale headphones, "After thinking for a long time, this moment has finally arrived." Timberwolves NBA Draft in '09 had been selected using the No. 5 pick Rubio, but in those days due to our prime buy-out fee, Rubio continues to be unable to make the trip. "We are here for Rubio opened his NBA career,wholesalers, very confident," Timberwolves President David - Kahn said, "We have by no means wavered." In the present news conference, the local time next Tuesday in Minnesota to Rubio arranged a media briefing, when he'll officially be introduced being a part of the Timberwolves.
"I felt he had created ??adequate preparations, it'll decide to visit NBA," Rubio said, "I want the earth's best players with the confrontation." Just Sui Barcelona obtaining Spanish basketball league championship Rubio, joined the NBA for your worst record last season, the Timberwolves have their own views, "I will probably join the team's frame of mind to create some changes," he said, "Maybe we do not have the strength of a championship, but we now have other objectives as long as help they achieve victory much more and much more I will do whatever the team requirements me to do. "Currently, Rubio hasn't and Minnesota for additional communication,wholesale women's shoes, he said that is unclear comprehension of their role within the team, but it is certain the Timberwolves hope Rubio to initial through training and get stronger. "(Within the NBA) game confrontational stronger," Rubio said,wholesale from china, "I need to increase how much,wholesale women's clothing, get stronger."

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你用排除法 吧。
其他貌似都有可能=0
如果有=0 最小值就不是2
B。有说了个区间。。
所以不一样。