0}} \right\\ \left \{ {{4(sinx -0.5)(sinx +3.5) =0} \atop {cosx<0}} \right\\" alt="\left \{ {{4sin^2x + 12sinx - 7 =0} \atop {-9cosx>0}} \right\\ \left \{ {{4(sinx -0.5)(sinx +3.5) =0} \atop {cosx<0}} \right\\" align="absmiddle" class="latex-formula">
' alt='x_{1} = \frac{\pi}{6}+2{\pi}n\\ x_{2} = \frac{5\pi}{6}+2{\pi}n\\ \frac{\pi}{2}+2{\pi}n' align="absmiddle" class="latex-formula">
x 1 не принадлежит
-9cosx=0
Ответ 
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