How do I solve 6/tg(x)^2-2*cos(x)^2 = 1.5

How do I solve 

$${\frac{{\mathtt{6}}}{{{tg}{\left({\mathtt{x}}\right)}}^{\,{\mathtt{2}}}}}{\mathtt{\,-\,}}{\mathtt{2}}{\mathtt{\,\times\,}}{\underset{\,\,\,\,^{\textcolor[rgb]{0.66,0.66,0.66}{360^\circ}}}{{cos}}{\left({\mathtt{x}}\right)}}^{\,{\mathtt{2}}} = {\mathtt{1.5}}$$