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tg2x<(-sqrt3/3) inequation

A inequation with variable

The solution

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              ___ 
           -\/ 3  
tan(2*x) < -------
              3   
$$\tan{\left(2 x \right)} < \frac{\left(-1\right) \sqrt{3}}{3}$$
tan(2*x) < (-sqrt(3))/3
Detail solution
Given the inequality:
$$\tan{\left(2 x \right)} < \frac{\left(-1\right) \sqrt{3}}{3}$$
To solve this inequality, we must first solve the corresponding equation:
$$\tan{\left(2 x \right)} = \frac{\left(-1\right) \sqrt{3}}{3}$$
Solve:
Given the equation
$$\tan{\left(2 x \right)} = \frac{\left(-1\right) \sqrt{3}}{3}$$
- this is the simplest trigonometric equation
This equation is transformed to
$$2 x = \pi n + \operatorname{atan}{\left(- \frac{\sqrt{3}}{3} \right)}$$
Or
$$2 x = \pi n - \frac{\pi}{6}$$
, where n - is a integer
Divide both parts of the equation by
$$2$$
$$x_{1} = \frac{\pi n}{2} - \frac{\pi}{12}$$
$$x_{1} = \frac{\pi n}{2} - \frac{\pi}{12}$$
This roots
$$x_{1} = \frac{\pi n}{2} - \frac{\pi}{12}$$
is the points with change the sign of the inequality expression.
First define with the sign to the leftmost point:
$$x_{0} < x_{1}$$
For example, let's take the point
$$x_{0} = x_{1} - \frac{1}{10}$$
=
$$\left(\frac{\pi n}{2} - \frac{\pi}{12}\right) + - \frac{1}{10}$$
=
$$\frac{\pi n}{2} - \frac{\pi}{12} - \frac{1}{10}$$
substitute to the expression
$$\tan{\left(2 x \right)} < \frac{\left(-1\right) \sqrt{3}}{3}$$
$$\tan{\left(2 \left(\frac{\pi n}{2} - \frac{\pi}{12} - \frac{1}{10}\right) \right)} < \frac{\left(-1\right) \sqrt{3}}{3}$$
                         ___ 
    /1   pi       \   -\/ 3  
-tan|- + -- - pi*n| < -------
    \5   6        /      3   
                      

the solution of our inequality is:
$$x < \frac{\pi n}{2} - \frac{\pi}{12}$$
 _____          
      \    
-------ο-------
       x1
Solving inequality on a graph
Rapid solution [src]
   /                 /  ___     ___\\
   |pi               |\/ 2  + \/ 6 ||
And|-- < x, x < -atan|-------------||
   |4                |  ___     ___||
   \                 \\/ 2  - \/ 6 //
$$\frac{\pi}{4} < x \wedge x < - \operatorname{atan}{\left(\frac{\sqrt{2} + \sqrt{6}}{- \sqrt{6} + \sqrt{2}} \right)}$$
(pi/4 < x)∧(x < -atan((sqrt(2) + sqrt(6))/(sqrt(2) - sqrt(6))))
Rapid solution 2 [src]
          /  ___     ___\ 
 pi       |\/ 2  + \/ 6 | 
(--, -atan|-------------|)
 4        |  ___     ___| 
          \\/ 2  - \/ 6 / 
$$x\ in\ \left(\frac{\pi}{4}, - \operatorname{atan}{\left(\frac{\sqrt{2} + \sqrt{6}}{- \sqrt{6} + \sqrt{2}} \right)}\right)$$
x in Interval.open(pi/4, -atan((sqrt(2) + sqrt(6))/(-sqrt(6) + sqrt(2))))