Given the inequality:
$$\cot{\left(x + \frac{\pi}{3} \right)} < -1$$
To solve this inequality, we must first solve the corresponding equation:
$$\cot{\left(x + \frac{\pi}{3} \right)} = -1$$
Solve:
$$x_{1} = - \frac{7 \pi}{12}$$
$$x_{1} = - \frac{7 \pi}{12}$$
This roots
$$x_{1} = - \frac{7 \pi}{12}$$
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
$$x_{0} = x_{1} - \frac{1}{10}$$
=
$$- \frac{7 \pi}{12} - \frac{1}{10}$$
=
$$- \frac{7 \pi}{12} - \frac{1}{10}$$
substitute to the expression
$$\cot{\left(x + \frac{\pi}{3} \right)} < -1$$
$$\cot{\left(\left(- \frac{7 \pi}{12} - \frac{1}{10}\right) + \frac{\pi}{3} \right)} < -1$$
/1 pi\
-cot|-- + --| < -1
\10 4 / but
/1 pi\
-cot|-- + --| > -1
\10 4 / Then
$$x < - \frac{7 \pi}{12}$$
no execute
the solution of our inequality is:
$$x > - \frac{7 \pi}{12}$$
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