net+resheniiy\right. \\\left \{ {{cos^2x\neq 0} \atop {3tg^2x+3tgx-5=0}} \right. \\\end{array}" alt="\left[\begin{array}{ccc}\left \{ {{cos^2x=0} \atop {sin^2x=0}}; cos^2x+sin^2x\neq 0=>net+resheniiy\right. \\\left \{ {{cos^2x\neq 0} \atop {3tg^2x+3tgx-5=0}} \right. \\\end{array}" align="absmiddle" class="latex-formula">
tgx=a; D=9+20*3=69
Ответ: x={arctg((-3±√69)/6)+pi*n}, n∈Z.