Mister Exam

sin2x<(\sqrt(3))/(2) inequation

A inequation with variable

The solution

You have entered [src]
             ___
           \/ 3 
sin(2*x) < -----
             2  
$$\sin{\left(2 x \right)} < \frac{\sqrt{3}}{2}$$
sin(2*x) < sqrt(3)/2
Detail solution
Given the inequality:
$$\sin{\left(2 x \right)} < \frac{\sqrt{3}}{2}$$
To solve this inequality, we must first solve the corresponding equation:
$$\sin{\left(2 x \right)} = \frac{\sqrt{3}}{2}$$
Solve:
Given the equation
$$\sin{\left(2 x \right)} = \frac{\sqrt{3}}{2}$$
- this is the simplest trigonometric equation
This equation is transformed to
$$2 x = 2 \pi n + \operatorname{asin}{\left(\frac{\sqrt{3}}{2} \right)}$$
$$2 x = 2 \pi n - \operatorname{asin}{\left(\frac{\sqrt{3}}{2} \right)} + \pi$$
Or
$$2 x = 2 \pi n + \frac{\pi}{3}$$
$$2 x = 2 \pi n + \frac{2 \pi}{3}$$
, where n - is a integer
Divide both parts of the equation by
$$2$$
$$x_{1} = \pi n + \frac{\pi}{6}$$
$$x_{2} = \pi n + \frac{\pi}{3}$$
$$x_{1} = \pi n + \frac{\pi}{6}$$
$$x_{2} = \pi n + \frac{\pi}{3}$$
This roots
$$x_{1} = \pi n + \frac{\pi}{6}$$
$$x_{2} = \pi n + \frac{\pi}{3}$$
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
$$x_{0} = x_{1} - \frac{1}{10}$$
=
$$\left(\pi n + \frac{\pi}{6}\right) + - \frac{1}{10}$$
=
$$\pi n - \frac{1}{10} + \frac{\pi}{6}$$
substitute to the expression
$$\sin{\left(2 x \right)} < \frac{\sqrt{3}}{2}$$
$$\sin{\left(2 \left(\pi n - \frac{1}{10} + \frac{\pi}{6}\right) \right)} < \frac{\sqrt{3}}{2}$$
                           ___
   /  1   pi         \   \/ 3 
sin|- - + -- + 2*pi*n| < -----
   \  5   3          /     2  
                         

one of the solutions of our inequality is:
$$x < \pi n + \frac{\pi}{6}$$
 _____           _____          
      \         /
-------ο-------ο-------
       x1      x2

Other solutions will get with the changeover to the next point
etc.
The answer:
$$x < \pi n + \frac{\pi}{6}$$
$$x > \pi n + \frac{\pi}{3}$$
Solving inequality on a graph
Rapid solution 2 [src]
    pi     pi     
[0, --) U (--, pi]
    6      3      
$$x\ in\ \left[0, \frac{\pi}{6}\right) \cup \left(\frac{\pi}{3}, \pi\right]$$
x in Union(Interval.Ropen(0, pi/6), Interval.Lopen(pi/3, pi))
Rapid solution [src]
  /   /            pi\     /         pi    \\
Or|And|0 <= x, x < --|, And|x <= pi, -- < x||
  \   \            6 /     \         3     //
$$\left(0 \leq x \wedge x < \frac{\pi}{6}\right) \vee \left(x \leq \pi \wedge \frac{\pi}{3} < x\right)$$
((0 <= x)∧(x < pi/6))∨((x <= pi)∧(pi/3 < x))