Question

помогите промежуток [5pi/2; 4pi]

Answer 1

$frac{3tg^2x}{sqrt{7cosx}} =0; ,; ; ODZ:; ; cosx textgreater 0; to ; -frac{pi}{2}+pi n textless x textless frac{pi}{2}+pi n,; nin Z\\tg^2x=0; ,tgx=0; to ; x=pi k; ,; kin Z\\ left { {{x=pi k} atop {-frac{pi}{2}+pi n textless x textless frac{pi}{2}+pi n}} right. ; Rightarrow ; ; x=2pi k,; kin Z\\xin [; frac{5pi }{2};4pi , ]; ; Rightarrow ; ; x=4pi ; .$