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tgx>=-1/2

tgx>=-1/2 inequation

A inequation with variable

The solution

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

but
-tan(1/10 + atan(1/2)) < -1/2

Then
$$x \leq \pi n - \operatorname{atan}{\left(\frac{1}{2} \right)}$$
no execute
the solution of our inequality is:
$$x \geq \pi n - \operatorname{atan}{\left(\frac{1}{2} \right)}$$
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Solving inequality on a graph
Rapid solution 2 [src]
    pi                        
[0, --) U [pi - atan(1/2), pi)
    2                         
$$x\ in\ \left[0, \frac{\pi}{2}\right) \cup \left[- \operatorname{atan}{\left(\frac{1}{2} \right)} + \pi, \pi\right)$$
x in Union(Interval.Ropen(0, pi/2), Interval.Ropen(pi - atan(1/2), pi))
Rapid solution [src]
  /   /            pi\                                  \
Or|And|0 <= x, x < --|, And(pi - atan(1/2) <= x, x < pi)|
  \   \            2 /                                  /
$$\left(0 \leq x \wedge x < \frac{\pi}{2}\right) \vee \left(- \operatorname{atan}{\left(\frac{1}{2} \right)} + \pi \leq x \wedge x < \pi\right)$$
((0 <= x)∧(x < pi/2))∨((x < pi)∧(pi - atan(1/2) <= x))
The graph
tgx>=-1/2 inequation