how to enter cosine (25 degrees) divided by 21 into calculator

cos(25)/21        should work fine

$${\frac{\underset{\,\,\,\,^{\textcolor[rgb]{0.66,0.66,0.66}{360^\circ}}}{{cos}}{\left({\mathtt{25}}^\circ\right)}}{{\mathtt{21}}}} = {\mathtt{0.043\: \!157\: \!513\: \!668\: \!428\: \!6}}$$