Mister Exam

tg3x>3/2 inequation

A inequation with variable

The solution

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tan(3*x) > 3/2
$$\tan{\left(3 x \right)} > \frac{3}{2}$$
tan(3*x) > 3/2
Detail solution
Given the inequality:
$$\tan{\left(3 x \right)} > \frac{3}{2}$$
To solve this inequality, we must first solve the corresponding equation:
$$\tan{\left(3 x \right)} = \frac{3}{2}$$
Solve:
Given the equation
$$\tan{\left(3 x \right)} = \frac{3}{2}$$
- this is the simplest trigonometric equation
This equation is transformed to
$$3 x = \pi n + \operatorname{atan}{\left(\frac{3}{2} \right)}$$
Or
$$3 x = \pi n + \operatorname{atan}{\left(\frac{3}{2} \right)}$$
, where n - is a integer
Divide both parts of the equation by
$$3$$
$$x_{1} = \frac{\pi n}{3} + \frac{\operatorname{atan}{\left(\frac{3}{2} \right)}}{3}$$
$$x_{1} = \frac{\pi n}{3} + \frac{\operatorname{atan}{\left(\frac{3}{2} \right)}}{3}$$
This roots
$$x_{1} = \frac{\pi n}{3} + \frac{\operatorname{atan}{\left(\frac{3}{2} \right)}}{3}$$
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
$$x_{0} = x_{1} - \frac{1}{10}$$
=
$$\left(\frac{\pi n}{3} + \frac{\operatorname{atan}{\left(\frac{3}{2} \right)}}{3}\right) + - \frac{1}{10}$$
=
$$\frac{\pi n}{3} - \frac{1}{10} + \frac{\operatorname{atan}{\left(\frac{3}{2} \right)}}{3}$$
substitute to the expression
$$\tan{\left(3 x \right)} > \frac{3}{2}$$
$$\tan{\left(3 \left(\frac{\pi n}{3} - \frac{1}{10} + \frac{\operatorname{atan}{\left(\frac{3}{2} \right)}}{3}\right) \right)} > \frac{3}{2}$$
tan(-3/10 + pi*n + atan(3/2)) > 3/2

Then
$$x < \frac{\pi n}{3} + \frac{\operatorname{atan}{\left(\frac{3}{2} \right)}}{3}$$
no execute
the solution of our inequality is:
$$x > \frac{\pi n}{3} + \frac{\operatorname{atan}{\left(\frac{3}{2} \right)}}{3}$$
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Solving inequality on a graph
Rapid solution [src]
   /           /      /   /  atan(12/5)   pi\\                                                               \    \
   |           |      |sin|- ---------- + --||      /    ___________________________________________________\|    |
   |    pi     |      |   \      6        6 /|      |   /    2/  atan(12/5)   pi\      2/  atan(12/5)   pi\ ||    |
And|x < --, -I*|I*atan|----------------------| + log|  /  cos |- ---------- + --| + sin |- ---------- + --| || < x|
   |    6      |      |   /  atan(12/5)   pi\|      \\/       \      6        6 /       \      6        6 / /|    |
   |           |      |cos|- ---------- + --||                                                               |    |
   \           \      \   \      6        6 //                                                               /    /
$$x < \frac{\pi}{6} \wedge - i \left(\log{\left(\sqrt{\sin^{2}{\left(- \frac{\operatorname{atan}{\left(\frac{12}{5} \right)}}{6} + \frac{\pi}{6} \right)} + \cos^{2}{\left(- \frac{\operatorname{atan}{\left(\frac{12}{5} \right)}}{6} + \frac{\pi}{6} \right)}} \right)} + i \operatorname{atan}{\left(\frac{\sin{\left(- \frac{\operatorname{atan}{\left(\frac{12}{5} \right)}}{6} + \frac{\pi}{6} \right)}}{\cos{\left(- \frac{\operatorname{atan}{\left(\frac{12}{5} \right)}}{6} + \frac{\pi}{6} \right)}} \right)}\right) < x$$
(x < pi/6)∧(-i*(i*atan(sin(-atan(12/5)/6 + pi/6)/cos(-atan(12/5)/6 + pi/6)) + log(sqrt(cos(-atan(12/5)/6 + pi/6)^2 + sin(-atan(12/5)/6 + pi/6)^2))) < x)