分离常数法求值域的问题1.f(x)=-2x+3/(x+1)2.f(x)=4x+2/(3x+1) x∈

网友回答

1.f(x)=-2x+3/(x+1)=[-2(x+1)+5]/(x+1)=-2+5/(x+1)
f(x)≠-2
2.f(x)=4x+2/(3x+1) =[4/3(3x+1)+2/3]/(3x+1) =4/3+2/3/(3x+1)
f(x)≠4/3 x∈[-2,-1/3)∪(-1/3,3)
f(x)∈[ 4/3+2/3/(3(-2)+1) ,4/3)∪( 4/3,4/3+2/3/(3(3)+1) )