求limx→-∞{[1-√(4x2+x+1)]/(4x+3)}
limx→-∞{[1-√(4x2+x+1)]/(4x+3)} =limx→-∞{[1-∣x∣√(4+1/x+1/x2)]/[x(4+3/x)]} =limx→-∞{[1/x+√(4+1/x+1/x2)]/(4+3/x)}=1/2.
求limx→-∞{[1-√(4x2+x+1)]/(4x+3)}
limx→-∞{[1-√(4x2+x+1)]/(4x+3)} =limx→-∞{[1-∣x∣√(4+1/x+1/x2)]/[x(4+3/x)]} =limx→-∞{[1/x+√(4+1/x+1/x2)]/(4+3/x)}=1/2.