$$\sin {\mkern 1mu} {15^ \circ }$$

$$\cos {\mkern 1mu} {15^ \circ }$$

$$\sin {\mkern 1mu} {15^ \circ }{\mkern 1mu} \cos {\mkern 1mu} {15^ \circ }$$

$$\sin {\mkern 1mu} {15^ \circ }{\mkern 1mu} \cos {\mkern 1mu} {75^ \circ }$$