11.求函数f(x)=x^2+2x+10/x+1(x>-1)的最值12.求函数f(x)=x^2+7x+10/x+1(x>-1)的值域.

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11.求函数f(x)=x^2+2x+10/x+1(x>-1)的最值12.求函数f(x)=x^2+7x+10/x+1(x>-1)的值域.
11.求函数f(x)=x^2+2x+10/x+1(x>-1)的最值
12.求函数f(x)=x^2+7x+10/x+1(x>-1)的值域.

11.求函数f(x)=x^2+2x+10/x+1(x>-1)的最值12.求函数f(x)=x^2+7x+10/x+1(x>-1)的值域.
11.
x>-1
f(x) = (x²+2x+10)/(x+1)
= {(x+1)²+9}/(x+1)
= (x+1) + 9/(x+1)
= {√(x+1) - 3/√(x+1)}²+6≥6
最小值6
12.
x>-1
f(x) = (x²+7x+10)/(x+1)
= {(x+1)²+5(x+1)+4}/(x+1)
= (x+1)+5+4/(x+1)
= {√(x+1)-2/(√x+1)}²+4+5≥9
值域【9,+∞)

11.f(x)=x^2+2x+10/(x+1)
f'(x)=2x+2-10/(x+1)^2
=[2(x+1)^3-10]/(x+1)^2
当-15^(1/3)-1时,f'(x)>0,
所以f(x)在(-1,5^(1/3)-1)为减函数,在(5^(1/3)-1,+∞)时为增函数,所以
当x=5^(1/3)-1时有最小值,最小值为f(5^(1/3)-1)=
12.类似来做。