Question 59
Determine all real numbers $x$ such that
$$
1 \le \frac{1 + \sin x}{1 - \sin x} \le 3.
$$
$$
1 \le \frac{1 + \sin x}{1 - \sin x} \le 3.
$$
MathNet 2018-part-02 — 181 problems (EN–VI) Question 59
Math Olympiad Vault · MathNet 2018-part-02 — 181 problems (EN–VI)