Mister Exam

Graphing y = x*asin(log(x))

v

The graph:

from to

Intersection points:

does show?

Piecewise:

The solution

You have entered [src]
f(x) = x*asin(log(x))
$$f{\left(x \right)} = x \operatorname{asin}{\left(\log{\left(x \right)} \right)}$$
f = x*asin(log(x))
The graph of the function
The points of intersection with the X-axis coordinate
Graph of the function intersects the axis X at f = 0
so we need to solve the equation:
$$x \operatorname{asin}{\left(\log{\left(x \right)} \right)} = 0$$
Solve this equation
The points of intersection with the axis X:

Analytical solution
$$x_{1} = 1$$
Numerical solution
$$x_{1} = 1$$
The points of intersection with the Y axis coordinate
The graph crosses Y axis when x equals 0:
substitute x = 0 to x*asin(log(x)).
$$0 \operatorname{asin}{\left(\log{\left(0 \right)} \right)}$$
The result:
$$f{\left(0 \right)} = \text{NaN}$$
- the solutions of the equation d'not exist
Extrema of the function
In order to find the extrema, we need to solve the equation
$$\frac{d}{d x} f{\left(x \right)} = 0$$
(the derivative equals zero),
and the roots of this equation are the extrema of this function:
$$\frac{d}{d x} f{\left(x \right)} = $$
the first derivative
$$\operatorname{asin}{\left(\log{\left(x \right)} \right)} + \frac{1}{\sqrt{1 - \log{\left(x \right)}^{2}}} = 0$$
Solve this equation
Solutions are not found,
function may have no extrema
Inflection points
Let's find the inflection points, we'll need to solve the equation for this
$$\frac{d^{2}}{d x^{2}} f{\left(x \right)} = 0$$
(the second derivative equals zero),
the roots of this equation will be the inflection points for the specified function graph:
$$\frac{d^{2}}{d x^{2}} f{\left(x \right)} = $$
the second derivative
$$\frac{1 - \frac{\log{\left(x \right)}}{\log{\left(x \right)}^{2} - 1}}{x \sqrt{1 - \log{\left(x \right)}^{2}}} = 0$$
Solve this equation
The roots of this equation
$$x_{1} = e^{\frac{1}{2} - \frac{\sqrt{5}}{2}}$$
$$x_{2} = e^{\frac{1}{2} + \frac{\sqrt{5}}{2}}$$

Сonvexity and concavity intervals:
Let’s find the intervals where the function is convex or concave, for this look at the behaviour of the function at the inflection points:
Concave at the intervals
$$\left[e^{\frac{1}{2} - \frac{\sqrt{5}}{2}}, \infty\right)$$
Convex at the intervals
$$\left(-\infty, e^{\frac{1}{2} - \frac{\sqrt{5}}{2}}\right]$$
Horizontal asymptotes
Let’s find horizontal asymptotes with help of the limits of this function at x->+oo and x->-oo
$$\lim_{x \to -\infty}\left(x \operatorname{asin}{\left(\log{\left(x \right)} \right)}\right) = \infty i$$
Let's take the limit
so,
horizontal asymptote on the left doesn’t exist
$$\lim_{x \to \infty}\left(x \operatorname{asin}{\left(\log{\left(x \right)} \right)}\right) = - \infty i$$
Let's take the limit
so,
horizontal asymptote on the right doesn’t exist
Inclined asymptotes
Inclined asymptote can be found by calculating the limit of x*asin(log(x)), divided by x at x->+oo and x ->-oo
$$\lim_{x \to -\infty} \operatorname{asin}{\left(\log{\left(x \right)} \right)} = - \infty i$$
Let's take the limit
so,
inclined asymptote on the left doesn’t exist
$$\lim_{x \to \infty} \operatorname{asin}{\left(\log{\left(x \right)} \right)} = - \infty i$$
Let's take the limit
so,
inclined asymptote on the right doesn’t exist
Even and odd functions
Let's check, whether the function even or odd by using relations f = f(-x) и f = -f(-x).
So, check:
$$x \operatorname{asin}{\left(\log{\left(x \right)} \right)} = - x \operatorname{asin}{\left(\log{\left(- x \right)} \right)}$$
- No
$$x \operatorname{asin}{\left(\log{\left(x \right)} \right)} = x \operatorname{asin}{\left(\log{\left(- x \right)} \right)}$$
- No
so, the function
not is
neither even, nor odd