Mister Exam

tg(3x)<1 inequation

A inequation with variable

The solution

You have entered [src]
tan(3*x) < 1
$$\tan{\left(3 x \right)} < 1$$
tan(3*x) < 1
Detail solution
Given the inequality:
$$\tan{\left(3 x \right)} < 1$$
To solve this inequality, we must first solve the corresponding equation:
$$\tan{\left(3 x \right)} = 1$$
Solve:
Given the equation
$$\tan{\left(3 x \right)} = 1$$
- this is the simplest trigonometric equation
This equation is transformed to
$$3 x = \pi n + \operatorname{atan}{\left(1 \right)}$$
Or
$$3 x = \pi n + \frac{\pi}{4}$$
, where n - is a integer
Divide both parts of the equation by
$$3$$
$$x_{1} = \frac{\pi n}{3} + \frac{\pi}{12}$$
$$x_{1} = \frac{\pi n}{3} + \frac{\pi}{12}$$
This roots
$$x_{1} = \frac{\pi n}{3} + \frac{\pi}{12}$$
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
$$x_{0} = x_{1} - \frac{1}{10}$$
=
$$\left(\frac{\pi n}{3} + \frac{\pi}{12}\right) + - \frac{1}{10}$$
=
$$\frac{\pi n}{3} - \frac{1}{10} + \frac{\pi}{12}$$
substitute to the expression
$$\tan{\left(3 x \right)} < 1$$
$$\tan{\left(3 \left(\frac{\pi n}{3} - \frac{1}{10} + \frac{\pi}{12}\right) \right)} < 1$$
   /  3    pi       \    
tan|- -- + -- + pi*n| < 1
   \  10   4        /    

the solution of our inequality is:
$$x < \frac{\pi n}{3} + \frac{\pi}{12}$$
 _____          
      \    
-------ο-------
       x1
Solving inequality on a graph
Rapid solution [src]
  /   /                /  ___     ___\\                      \
  |   |                |\/ 6  - \/ 2 ||     /     pi  pi    \|
Or|And|0 <= x, x < atan|-------------||, And|x <= --, -- < x||
  |   |                |  ___     ___||     \     3   6     /|
  \   \                \\/ 2  + \/ 6 //                      /
$$\left(0 \leq x \wedge x < \operatorname{atan}{\left(\frac{- \sqrt{2} + \sqrt{6}}{\sqrt{2} + \sqrt{6}} \right)}\right) \vee \left(x \leq \frac{\pi}{3} \wedge \frac{\pi}{6} < x\right)$$
((x <= pi/3)∧(pi/6 < x))∨((0 <= x)∧(x < atan((sqrt(6) - sqrt(2))/(sqrt(2) + sqrt(6)))))
Rapid solution 2 [src]
         /  ___     ___\            
         |\/ 2  - \/ 6 |     pi  pi 
[0, -atan|-------------|) U (--, --]
         |  ___     ___|     6   3  
         \\/ 2  + \/ 6 /            
$$x\ in\ \left[0, - \operatorname{atan}{\left(\frac{- \sqrt{6} + \sqrt{2}}{\sqrt{2} + \sqrt{6}} \right)}\right) \cup \left(\frac{\pi}{6}, \frac{\pi}{3}\right]$$
x in Union(Interval.Ropen(0, -atan((-sqrt(6) + sqrt(2))/(sqrt(2) + sqrt(6)))), Interval.Lopen(pi/6, pi/3))