Given the inequality:
$$\left(- 36 \cdot 3^{x^{2} - 3} + 9^{x^{2} - 1}\right) + 3 \leq 0$$
To solve this inequality, we must first solve the corresponding equation:
$$\left(- 36 \cdot 3^{x^{2} - 3} + 9^{x^{2} - 1}\right) + 3 = 0$$
Solve:
$$x_{1} = -1$$
$$x_{2} = 1$$
$$x_{3} = - \sqrt{2}$$
$$x_{4} = \sqrt{2}$$
$$x_{1} = -1$$
$$x_{2} = 1$$
$$x_{3} = - \sqrt{2}$$
$$x_{4} = \sqrt{2}$$
This roots
$$x_{3} = - \sqrt{2}$$
$$x_{1} = -1$$
$$x_{2} = 1$$
$$x_{4} = \sqrt{2}$$
is the points with change the sign of the inequality expression.
First define with the sign to the leftmost point:
$$x_{0} \leq x_{3}$$
For example, let's take the point
$$x_{0} = x_{3} - \frac{1}{10}$$
=
$$- \sqrt{2} - \frac{1}{10}$$
=
$$- \sqrt{2} - \frac{1}{10}$$
substitute to the expression
$$\left(- 36 \cdot 3^{x^{2} - 3} + 9^{x^{2} - 1}\right) + 3 \leq 0$$
$$\left(- 36 \cdot 3^{-3 + \left(- \sqrt{2} - \frac{1}{10}\right)^{2}} + 9^{-1 + \left(- \sqrt{2} - \frac{1}{10}\right)^{2}}\right) + 3 \leq 0$$
2 2
/ 1 ___\ / 1 ___\
-1 + |- -- - \/ 2 | -3 + |- -- - \/ 2 | <= 0
\ 10 / \ 10 /
3 + 9 - 36*3 but
2 2
/ 1 ___\ / 1 ___\
-1 + |- -- - \/ 2 | -3 + |- -- - \/ 2 | >= 0
\ 10 / \ 10 /
3 + 9 - 36*3 Then
$$x \leq - \sqrt{2}$$
no execute
one of the solutions of our inequality is:
$$x \geq - \sqrt{2} \wedge x \leq -1$$
_____ _____
/ \ / \
-------•-------•-------•-------•-------
x3 x1 x2 x4Other solutions will get with the changeover to the next point
etc.
The answer:
$$x \geq - \sqrt{2} \wedge x \leq -1$$
$$x \geq 1 \wedge x \leq \sqrt{2}$$