limit as x approaches infinity of ((e^{-xy-x+y}))/(x^2y^2+xy)

解答

x \to \infty lim (\frac{( e ^{- x y - x + y} )}{x ^{2} y ^{2} + x y})

0

求解步骤

x \to \infty lim (\frac{e ^{- x y - x + y}}{x ^{2} y ^{2} + x y})

化简

e^{- x y - x + y} : e^{- x y} e^{- x} e^{y}

= x \to \infty lim (\frac{e ^{- x y} e ^{- x} e ^{y}}{x ^{2} y ^{2} + x y})

x \to a lim [c \cdot f (x)] = c \cdot x \to a lim f (x)

= e^{y} \cdot x \to \infty lim (\frac{e ^{- x y} e ^{- x}}{x ^{2} y ^{2} + x y})

x \to a lim [\frac{f ( x )}{g ( x )}] = \frac{lim _{x \to a} f ( x )}{lim _{x \to a} g ( x )}, x \to a lim g (x) \neq = 0

不定型除外

= e^{y} \frac{lim _{x \to \infty} ( e ^{- x y} e ^{- x} )}{lim _{x \to \infty} ( x ^{2} y ^{2} + x y )}

x \to \infty lim (e^{- x y} e^{- x}) = 0

x \to \infty lim (x^{2} y^{2} + x y) = \infty

= e^{y} \frac{0}{\infty}

化简

e^{y} \frac{0}{\infty} : 0

= 0

y^{^{''}} - 2 y^{^{'}} + 8 y = 320 t^{2}

d er i v a t i v e \frac{1}{3 x}

x \to 4 lim (\frac{x + 4}{x - 4})

\int \frac{t}{e ^{3 t}} d t

\int (\frac{1}{x ^{2} - 1}) d x