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sinx>=0,2 inequation

A inequation with variable

The solution

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sin(x) >= 1/5
$$\sin{\left(x \right)} \geq \frac{1}{5}$$
sin(x) >= 1/5
Detail solution
Given the inequality:
$$\sin{\left(x \right)} \geq \frac{1}{5}$$
To solve this inequality, we must first solve the corresponding equation:
$$\sin{\left(x \right)} = \frac{1}{5}$$
Solve:
Given the equation
$$\sin{\left(x \right)} = \frac{1}{5}$$
- this is the simplest trigonometric equation
This equation is transformed to
$$x = 2 \pi n + \operatorname{asin}{\left(\frac{1}{5} \right)}$$
$$x = 2 \pi n - \operatorname{asin}{\left(\frac{1}{5} \right)} + \pi$$
Or
$$x = 2 \pi n + \operatorname{asin}{\left(\frac{1}{5} \right)}$$
$$x = 2 \pi n - \operatorname{asin}{\left(\frac{1}{5} \right)} + \pi$$
, where n - is a integer
$$x_{1} = 2 \pi n + \operatorname{asin}{\left(\frac{1}{5} \right)}$$
$$x_{2} = 2 \pi n - \operatorname{asin}{\left(\frac{1}{5} \right)} + \pi$$
$$x_{1} = 2 \pi n + \operatorname{asin}{\left(\frac{1}{5} \right)}$$
$$x_{2} = 2 \pi n - \operatorname{asin}{\left(\frac{1}{5} \right)} + \pi$$
This roots
$$x_{1} = 2 \pi n + \operatorname{asin}{\left(\frac{1}{5} \right)}$$
$$x_{2} = 2 \pi n - \operatorname{asin}{\left(\frac{1}{5} \right)} + \pi$$
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
$$x_{0} = x_{1} - \frac{1}{10}$$
=
$$\left(2 \pi n + \operatorname{asin}{\left(\frac{1}{5} \right)}\right) + - \frac{1}{10}$$
=
$$2 \pi n - \frac{1}{10} + \operatorname{asin}{\left(\frac{1}{5} \right)}$$
substitute to the expression
$$\sin{\left(x \right)} \geq \frac{1}{5}$$
$$\sin{\left(2 \pi n - \frac{1}{10} + \operatorname{asin}{\left(\frac{1}{5} \right)} \right)} \geq \frac{1}{5}$$
sin(-1/10 + 2*pi*n + asin(1/5)) >= 1/5

but
sin(-1/10 + 2*pi*n + asin(1/5)) < 1/5

Then
$$x \leq 2 \pi n + \operatorname{asin}{\left(\frac{1}{5} \right)}$$
no execute
one of the solutions of our inequality is:
$$x \geq 2 \pi n + \operatorname{asin}{\left(\frac{1}{5} \right)} \wedge x \leq 2 \pi n - \operatorname{asin}{\left(\frac{1}{5} \right)} + \pi$$
         _____  
        /     \  
-------•-------•-------
       x1      x2
Solving inequality on a graph
Rapid solution [src]
   /              /  ___\      /  ___\     \
   |              |\/ 6 |      |\/ 6 |     |
And|x <= pi - atan|-----|, atan|-----| <= x|
   \              \  12 /      \  12 /     /
$$x \leq \pi - \operatorname{atan}{\left(\frac{\sqrt{6}}{12} \right)} \wedge \operatorname{atan}{\left(\frac{\sqrt{6}}{12} \right)} \leq x$$
(atan(sqrt(6)/12) <= x)∧(x <= pi - atan(sqrt(6)/12))
Rapid solution 2 [src]
     /  ___\           /  ___\ 
     |\/ 6 |           |\/ 6 | 
[atan|-----|, pi - atan|-----|]
     \  12 /           \  12 / 
$$x\ in\ \left[\operatorname{atan}{\left(\frac{\sqrt{6}}{12} \right)}, \pi - \operatorname{atan}{\left(\frac{\sqrt{6}}{12} \right)}\right]$$
x in Interval(atan(sqrt(6)/12), pi - atan(sqrt(6)/12))