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tan(x)<=-1/3 inequation

A inequation with variable

The solution

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tan(x) <= -1/3
$$\tan{\left(x \right)} \leq - \frac{1}{3}$$
tan(x) <= -1/3
Detail solution
Given the inequality:
$$\tan{\left(x \right)} \leq - \frac{1}{3}$$
To solve this inequality, we must first solve the corresponding equation:
$$\tan{\left(x \right)} = - \frac{1}{3}$$
Solve:
Given the equation
$$\tan{\left(x \right)} = - \frac{1}{3}$$
- this is the simplest trigonometric equation
This equation is transformed to
$$x = \pi n + \operatorname{atan}{\left(- \frac{1}{3} \right)}$$
Or
$$x = \pi n - \operatorname{atan}{\left(\frac{1}{3} \right)}$$
, where n - is a integer
$$x_{1} = \pi n - \operatorname{atan}{\left(\frac{1}{3} \right)}$$
$$x_{1} = \pi n - \operatorname{atan}{\left(\frac{1}{3} \right)}$$
This roots
$$x_{1} = \pi n - \operatorname{atan}{\left(\frac{1}{3} \right)}$$
is the points with change the sign of the inequality expression.
First define with the sign to the leftmost point:
$$x_{0} \leq x_{1}$$
For example, let's take the point
$$x_{0} = x_{1} - \frac{1}{10}$$
=
$$\left(\pi n - \operatorname{atan}{\left(\frac{1}{3} \right)}\right) + - \frac{1}{10}$$
=
$$\pi n - \operatorname{atan}{\left(\frac{1}{3} \right)} - \frac{1}{10}$$
substitute to the expression
$$\tan{\left(x \right)} \leq - \frac{1}{3}$$
$$\tan{\left(\pi n - \operatorname{atan}{\left(\frac{1}{3} \right)} - \frac{1}{10} \right)} \leq - \frac{1}{3}$$
-tan(1/10 - pi*n + atan(1/3)) <= -1/3

the solution of our inequality is:
$$x \leq \pi n - \operatorname{atan}{\left(\frac{1}{3} \right)}$$
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Solving inequality on a graph
Rapid solution [src]
   /                     pi    \
And|x <= pi - atan(1/3), -- < x|
   \                     2     /
$$x \leq \pi - \operatorname{atan}{\left(\frac{1}{3} \right)} \wedge \frac{\pi}{2} < x$$
(pi/2 < x)∧(x <= pi - atan(1/3))
Rapid solution 2 [src]
 pi                 
(--, pi - atan(1/3)]
 2                  
$$x\ in\ \left(\frac{\pi}{2}, \pi - \operatorname{atan}{\left(\frac{1}{3} \right)}\right]$$
x in Interval.Lopen(pi/2, pi - atan(1/3))