L'Hôspital Rule

Suppose f(x) and g(x) are differentiable and g (x)0 on an open interval that contains ω except possibly at ω. Suppose

  • either limxω f(x)=0 and limxω g(x)=0
  • or limxω f(x)=± and limxω f(x)=±

Then

limxω f(x) g(x) = f(x) g(x)

provided the limit on the right exists.

0/0

limx0 1-cosx x limx1 sin(πx) lnx limx 1x -1 1x limx0 sinx-x x

/

limx 3x+5 2x-1 limx 0+ ln(x) 1/tan(x) limx ln(x) x limx x x

Caution

lim x1 x2+5 3x-4 limx x-sinx x

Other forms

0×0
lim x0+ (xlnx)
-
limx 0- ( 1x - 1sinx ) limx 0+ ( 1x2 - 1tanx )
0
limx x1x
00
limx 0+ xx limx 0+ xsinx
1
limx 0+ (1+x) 1x