Mister Exam

Other calculators


sin2x>-sqrt3/2

sin2x>-sqrt3/2 inequation

A inequation with variable

The solution

You have entered [src]
              ___ 
           -\/ 3  
sin(2*x) > -------
              2   
$$\sin{\left(2 x \right)} > \frac{\left(-1\right) \sqrt{3}}{2}$$
sin(2*x) > -sqrt(3)/2
Detail solution
Given the inequality:
$$\sin{\left(2 x \right)} > \frac{\left(-1\right) \sqrt{3}}{2}$$
To solve this inequality, we must first solve the corresponding equation:
$$\sin{\left(2 x \right)} = \frac{\left(-1\right) \sqrt{3}}{2}$$
Solve:
Given the equation
$$\sin{\left(2 x \right)} = \frac{\left(-1\right) \sqrt{3}}{2}$$
- 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
$$2 x = 2 \pi n - \frac{\pi}{3}$$
$$2 x = 2 \pi n + \frac{4 \pi}{3}$$
, where n - is a integer
Divide both parts of the equation by
$$2$$
$$x_{1} = \pi n - \frac{\pi}{6}$$
$$x_{2} = \pi n + \frac{2 \pi}{3}$$
$$x_{1} = \pi n - \frac{\pi}{6}$$
$$x_{2} = \pi n + \frac{2 \pi}{3}$$
This roots
$$x_{1} = \pi n - \frac{\pi}{6}$$
$$x_{2} = \pi n + \frac{2 \pi}{3}$$
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
$$x_{0} = x_{1} - \frac{1}{10}$$
=
$$\left(\pi n - \frac{\pi}{6}\right) - \frac{1}{10}$$
=
$$\pi n - \frac{\pi}{6} - \frac{1}{10}$$
substitute to the expression
$$\sin{\left(2 x \right)} > \frac{\left(-1\right) \sqrt{3}}{2}$$
$$\sin{\left(2 \left(\pi n - \frac{\pi}{6} - \frac{1}{10}\right) \right)} > \frac{\left(-1\right) \sqrt{3}}{2}$$
                  ___ 
    /1   pi\   -\/ 3  
-sin|- + --| > -------
    \5   3 /      2   
               

Then
$$x < \pi n - \frac{\pi}{6}$$
no execute
one of the solutions of our inequality is:
$$x > \pi n - \frac{\pi}{6} \wedge x < \pi n + \frac{2 \pi}{3}$$
         _____  
        /     \  
-------ο-------ο-------
       x_1      x_2
Solving inequality on a graph
Rapid solution [src]
  /   /            2*pi\     /5*pi            \\
Or|And|0 <= x, x < ----|, And|---- < x, x < pi||
  \   \             3  /     \ 6              //
$$\left(0 \leq x \wedge x < \frac{2 \pi}{3}\right) \vee \left(\frac{5 \pi}{6} < x \wedge x < \pi\right)$$
((0 <= x)∧(x < 2*pi/3))∨((x < pi)∧(5*pi/6 < x))
Rapid solution 2 [src]
    2*pi     5*pi     
[0, ----) U (----, pi)
     3        6       
$$x\ in\ \left[0, \frac{2 \pi}{3}\right) \cup \left(\frac{5 \pi}{6}, \pi\right)$$
x in Union(Interval.Ropen(0, 2*pi/3), Interval.open(5*pi/6, pi))
The graph
sin2x>-sqrt3/2 inequation