<span>1/tg</span>²<span>x+1/Sinx+3=0 cos²x/sin²x + 1/sinx + 3 = 0</span><span>(cos</span>²<span>x + sinx + 3sin</span>²<span>x) / sin²x = 0,</span><span> sin ^2x ≠ 0, x ≠ </span>πk, k∈<span>Z; </span><span> 1 - <span> sin </span></span>²<span><span>x + sinx + 3sin</span></span>²<span><span>x = 0</span></span>2sin²x + sinx + 1 = 0
D < 0, решений нет
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