函数f(x)=根号【2-(x+7)/(x+2)】的定义域为A,g(x)=lg【(2x+b)(ax+1)】(b>0,a∈R)函数f(x)=根号【2-(x+7)/(x+2)】的定义域为A,g(x)=lg【(2x+b)(ax+1)】(b>0,a∈R)的定义域为B.若A包含于B,求a,b的
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![函数f(x)=根号【2-(x+7)/(x+2)】的定义域为A,g(x)=lg【(2x+b)(ax+1)】(b>0,a∈R)函数f(x)=根号【2-(x+7)/(x+2)】的定义域为A,g(x)=lg【(2x+b)(ax+1)】(b>0,a∈R)的定义域为B.若A包含于B,求a,b的](/uploads/image/z/14491274-50-4.jpg?t=%E5%87%BD%E6%95%B0f%28x%29%3D%E6%A0%B9%E5%8F%B7%E3%80%902-%28x%2B7%29%2F%28x%2B2%29%E3%80%91%E7%9A%84%E5%AE%9A%E4%B9%89%E5%9F%9F%E4%B8%BAA%2Cg%28x%29%3Dlg%E3%80%90%282x%2Bb%29%28ax%2B1%29%E3%80%91%28b%3E0%2Ca%E2%88%88R%29%E5%87%BD%E6%95%B0f%EF%BC%88x%EF%BC%89%3D%E6%A0%B9%E5%8F%B7%E3%80%902-%EF%BC%88x%2B7%EF%BC%89%2F%EF%BC%88x%2B2%EF%BC%89%E3%80%91%E7%9A%84%E5%AE%9A%E4%B9%89%E5%9F%9F%E4%B8%BAA%2Cg%EF%BC%88x%EF%BC%89%3Dlg%E3%80%90%EF%BC%882x%2Bb%EF%BC%89%EF%BC%88ax%2B1%EF%BC%89%E3%80%91%EF%BC%88b%EF%BC%9E0%2Ca%E2%88%88R%EF%BC%89%E7%9A%84%E5%AE%9A%E4%B9%89%E5%9F%9F%E4%B8%BAB.%E8%8B%A5A%E5%8C%85%E5%90%AB%E4%BA%8EB%2C%E6%B1%82a%2Cb%E7%9A%84)
函数f(x)=根号【2-(x+7)/(x+2)】的定义域为A,g(x)=lg【(2x+b)(ax+1)】(b>0,a∈R)函数f(x)=根号【2-(x+7)/(x+2)】的定义域为A,g(x)=lg【(2x+b)(ax+1)】(b>0,a∈R)的定义域为B.若A包含于B,求a,b的
函数f(x)=根号【2-(x+7)/(x+2)】的定义域为A,g(x)=lg【(2x+b)(ax+1)】(b>0,a∈R)
函数f(x)=根号【2-(x+7)/(x+2)】的定义域为A,g(x)=lg【(2x+b)(ax+1)】(b>0,a∈R)的定义域为B.若A包含于B,求a,b的取值范围.
函数f(x)=根号【2-(x+7)/(x+2)】的定义域为A,g(x)=lg【(2x+b)(ax+1)】(b>0,a∈R)函数f(x)=根号【2-(x+7)/(x+2)】的定义域为A,g(x)=lg【(2x+b)(ax+1)】(b>0,a∈R)的定义域为B.若A包含于B,求a,b的
函数f(x)=根号【2-(x+7)/(x+2)】的定义域为A,g(x)=lg【(2x+b)(ax+1)】(b>0,a∈R)的定义域为B.若A包含于B,求a,b的取值范围.
解析:函数f(x)= √[2-(x+7)/(x+2)]
A:2-(x+7)/(x+2)>=0==>2(x+2)>=(x+7) ==>x>=3
G(x)=lg[(2x+b)(ax+1)](b>0,a∈R)
(2x+b)(ax+1)>0
B:
当a>0且ab>2时,x-1/a
当a>0且ab=2时,x≠-(ab+2)/(4a)
当a>0且ab-b/2
当a2时,-b/20且ab=2时,x≠-(ab+2)/(4a)b>0
当a>0且ab-2/3,取b>0
当a=0时,-b/2-6,取b>0
当a2时,-b/2
f(x)=根号【2-(x+7)/(x+2)】的定义域为A
2-(x+7)/(x+2)≥0
得x<-2或x≥3
A={x|x<-2或x≥3}
g(x)=lg【(2x+b)(ax+1)】(b>0,a∈R)的定义域为B
令h(x)=(2x+b)(ax+1)>0
因为A包含于B
所以必为开口向上抛物线
a>0,h(x)=0的两根为-b/2和-...
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f(x)=根号【2-(x+7)/(x+2)】的定义域为A
2-(x+7)/(x+2)≥0
得x<-2或x≥3
A={x|x<-2或x≥3}
g(x)=lg【(2x+b)(ax+1)】(b>0,a∈R)的定义域为B
令h(x)=(2x+b)(ax+1)>0
因为A包含于B
所以必为开口向上抛物线
a>0,h(x)=0的两根为-b/2和-1/a
由题意-b/2和-1/a均<0
-b/2≥-2且-1/a≥-2
得b≤4,a≥1/2
所以:01/2
收起
f(x)=根号【2-(x+7)/(x+2)】的定义域为A,
即(x+7)/(x+2)<=2 且X不等于-2
解得x>3
g(x)=lg【(2x+b)(ax+1)】(b>0,a∈R)的定义域为B
若A包含于B
即 lg(2x+b)+lg(ax+1), 2x+b>1 ; ax+1>1;其中x>3
解得a>-5; b>-1/3。.