Question

помогите решить 16ое неравенство!

Answer 1

$cos^{2} 2x textgreater frac{2+ sqrt{3} }{4} \ frac{1+cos4x}{2} textgreater frac{2+ sqrt{3} }{4}|*4 \ 2+2cos4x textgreater 2+ sqrt{3} \ cos4x textgreater frac{ sqrt{3} }{2} \ cos4x= frac{ sqrt{3} }{2} \ 4x= left { {{+} atop {-}} right. frac{ pi }{6} +2 pi n; \ x= left { {{+} atop {-}} right. frac{ pi }{24} + frac{ pi n}{2}$
,n∈Z
$-frac{ pi }{24} + frac{ pi n}{2} textless x textless frac{ pi }{24} + frac{ pi n}{2}$
отв:x∈(-π/24 + πn/2;π/24 + πn/2),n∈Z