Mister Exam

Other calculators:


x-sqrt(x^2-x)

Limit of the function x-sqrt(x^2-x)

at
v

For end points:

The graph:

from to

Piecewise:

The solution

You have entered [src]
     /       ________\
     |      /  2     |
 lim \x - \/  x  - x /
x->oo                 
$$\lim_{x \to \infty}\left(x - \sqrt{x^{2} - x}\right)$$
Limit(x - sqrt(x^2 - x), x, oo, dir='-')
Detail solution
Let's take the limit
$$\lim_{x \to \infty}\left(x - \sqrt{x^{2} - x}\right)$$
Let's eliminate indeterminateness oo - oo
Multiply and divide by
$$x + \sqrt{x^{2} - x}$$
then
$$\lim_{x \to \infty}\left(x - \sqrt{x^{2} - x}\right)$$
=
$$\lim_{x \to \infty}\left(\frac{\left(x - \sqrt{x^{2} - x}\right) \left(x + \sqrt{x^{2} - x}\right)}{x + \sqrt{x^{2} - x}}\right)$$
=
$$\lim_{x \to \infty}\left(\frac{x^{2} - \left(\sqrt{x^{2} - x}\right)^{2}}{x + \sqrt{x^{2} - x}}\right)$$
=
$$\lim_{x \to \infty}\left(\frac{x}{x + \sqrt{x^{2} - x}}\right)$$
=
$$\lim_{x \to \infty}\left(\frac{x}{x + \sqrt{x^{2} - x}}\right)$$

Let's divide numerator and denominator by x:
$$\lim_{x \to \infty} \frac{1}{1 + \frac{\sqrt{x^{2} - x}}{x}}$$ =
$$\lim_{x \to \infty} \frac{1}{\sqrt{\frac{x^{2} - x}{x^{2}}} + 1}$$ =
$$\lim_{x \to \infty} \frac{1}{\sqrt{1 - \frac{1}{x}} + 1}$$
Do replacement
$$u = \frac{1}{x}$$
then
$$\lim_{x \to \infty} \frac{1}{\sqrt{1 - \frac{1}{x}} + 1}$$ =
$$\lim_{u \to 0^+} \frac{1}{\sqrt{1 - u} + 1}$$ =
= $$\frac{1}{1 + \sqrt{1 - 0}} = \frac{1}{2}$$

The final answer:
$$\lim_{x \to \infty}\left(x - \sqrt{x^{2} - x}\right) = \frac{1}{2}$$
Lopital's rule
There is no sense to apply Lopital's rule to this function since there is no indeterminateness of 0/0 or oo/oo type
The graph
Other limits x→0, -oo, +oo, 1
$$\lim_{x \to \infty}\left(x - \sqrt{x^{2} - x}\right) = \frac{1}{2}$$
$$\lim_{x \to 0^-}\left(x - \sqrt{x^{2} - x}\right) = 0$$
More at x→0 from the left
$$\lim_{x \to 0^+}\left(x - \sqrt{x^{2} - x}\right) = 0$$
More at x→0 from the right
$$\lim_{x \to 1^-}\left(x - \sqrt{x^{2} - x}\right) = 1$$
More at x→1 from the left
$$\lim_{x \to 1^+}\left(x - \sqrt{x^{2} - x}\right) = 1$$
More at x→1 from the right
$$\lim_{x \to -\infty}\left(x - \sqrt{x^{2} - x}\right) = -\infty$$
More at x→-oo
Rapid solution [src]
1/2
$$\frac{1}{2}$$
The graph
Limit of the function x-sqrt(x^2-x)