limit as x approaches 4+of (4-x)/(|4-x|)

解答

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

- 1

求解步骤

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

当

x \to 4 +

时,

4 - x

为负. 因此

∣ 4 - x ∣ = - 4 + x

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

\frac{4 - x}{- 4 + x} = - 1

= x \to 4 + lim (- 1)

x \to a lim c = c

= - 1

\frac{d}{d x} (- 5 x e^{x})

d er i v a t i v e e^{5 t s i n (2 t)}

a re a e^{x}, x e^{x}, 0

\frac{\partial}{\partial x} (x^{2} + y^{2} + z^{2} - 25)

y^{^{'}} + 2 y = 2 x + e^{4 x}