$${\underset{\,\,\,\,^{\textcolor[rgb]{0.66,0.66,0.66}{360^\circ}}}{{cos}}{\left({\mathtt{45}}^\circ\right)}}^{\,{\mathtt{2}}} = {\frac{{\mathtt{1}}}{{\mathtt{2}}}} = {\mathtt{0.500\: \!000\: \!000\: \!000\: \!639\: \!9}}$$
you type it in as cos(x)^2