Question

1) 2 cos 3 x = $sqrt{3}$

2) (2/5)$x^{x ^{2} -5+6}$ <1

Answer 1

$1); ; 2cos3x=sqrt3\\cos3x=frac{sqrt3}{2}\\3x=pm frac{pi}{6}+2pi n,; nin Z\\x=pm frac{pi}{18}+frac{2pi n}{3}; ,; nin Z$

$2); ; frac{2}{5}x^2-5+6 textless 1\\frac{2}{5}x^2 textless 0; ; net; reshenij; ,; t.k.; x^2 geq 0$  

3)$(frac{2}{5})^{x^2-5x+6}<1;1=(frac{2}{5})^0$

$x^2-5x+6 textgreater 0\\x_1=2,x_2=3\\+++(2)---(3)+++\\xin(-infty, 2)cup(3,+infty)$