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(-1+x)/(-5+x^2+4*x)

Limit of the function (-1+x)/(-5+x^2+4*x)

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The solution

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     /    -1 + x   \
 lim |-------------|
x->1+|      2      |
     \-5 + x  + 4*x/
$$\lim_{x \to 1^+}\left(\frac{x - 1}{x^{2} + 4 x - 5}\right)$$
Limit((-1 + x)/(-5 + x^2 + 4*x), x, 1)
Detail solution
Let's take the limit
$$\lim_{x \to 1^+}\left(\frac{x - 1}{x^{2} + 4 x - 5}\right)$$
transform
$$\lim_{x \to 1^+}\left(\frac{x - 1}{x^{2} + 4 x - 5}\right)$$
=
$$\lim_{x \to 1^+}\left(\frac{x - 1}{\left(x - 1\right) \left(x + 5\right)}\right)$$
=
$$\lim_{x \to 1^+} \frac{1}{x + 5} = $$
$$\frac{1}{1 + 5} = $$
= 1/6

The final answer:
$$\lim_{x \to 1^+}\left(\frac{x - 1}{x^{2} + 4 x - 5}\right) = \frac{1}{6}$$
Lopital's rule
We have indeterminateness of type
0/0,

i.e. limit for the numerator is
$$\lim_{x \to 1^+}\left(x - 1\right) = 0$$
and limit for the denominator is
$$\lim_{x \to 1^+}\left(x^{2} + 4 x - 5\right) = 0$$
Let's take derivatives of the numerator and denominator until we eliminate indeterninateness.
$$\lim_{x \to 1^+}\left(\frac{x - 1}{x^{2} + 4 x - 5}\right)$$
=
$$\lim_{x \to 1^+}\left(\frac{\frac{d}{d x} \left(x - 1\right)}{\frac{d}{d x} \left(x^{2} + 4 x - 5\right)}\right)$$
=
$$\lim_{x \to 1^+} \frac{1}{2 x + 4}$$
=
$$\lim_{x \to 1^+} \frac{1}{2 x + 4}$$
=
$$\frac{1}{6}$$
It can be seen that we have applied Lopital's rule (we have taken derivatives with respect to the numerator and denominator) 1 time(s)
The graph
Rapid solution [src]
1/6
$$\frac{1}{6}$$
Other limits x→0, -oo, +oo, 1
$$\lim_{x \to 1^-}\left(\frac{x - 1}{x^{2} + 4 x - 5}\right) = \frac{1}{6}$$
More at x→1 from the left
$$\lim_{x \to 1^+}\left(\frac{x - 1}{x^{2} + 4 x - 5}\right) = \frac{1}{6}$$
$$\lim_{x \to \infty}\left(\frac{x - 1}{x^{2} + 4 x - 5}\right) = 0$$
More at x→oo
$$\lim_{x \to 0^-}\left(\frac{x - 1}{x^{2} + 4 x - 5}\right) = \frac{1}{5}$$
More at x→0 from the left
$$\lim_{x \to 0^+}\left(\frac{x - 1}{x^{2} + 4 x - 5}\right) = \frac{1}{5}$$
More at x→0 from the right
$$\lim_{x \to -\infty}\left(\frac{x - 1}{x^{2} + 4 x - 5}\right) = 0$$
More at x→-oo
One‐sided limits [src]
     /    -1 + x   \
 lim |-------------|
x->1+|      2      |
     \-5 + x  + 4*x/
$$\lim_{x \to 1^+}\left(\frac{x - 1}{x^{2} + 4 x - 5}\right)$$
1/6
$$\frac{1}{6}$$
= 0.166666666666667
     /    -1 + x   \
 lim |-------------|
x->1-|      2      |
     \-5 + x  + 4*x/
$$\lim_{x \to 1^-}\left(\frac{x - 1}{x^{2} + 4 x - 5}\right)$$
1/6
$$\frac{1}{6}$$
= 0.166666666666667
= 0.166666666666667
Numerical answer [src]
0.166666666666667
0.166666666666667
The graph
Limit of the function (-1+x)/(-5+x^2+4*x)