Which one of the following number (s) is/are rational?

we have,sin⁡15∘=sin⁡(45∘−30∘)=3−122⇒ sin⁡15∘=14(6−2) which is an irrational number     cos⁡15∘=cos⁡(45∘−30∘)=−3+122⇒ cos⁡15∘=14(6+2) which is an irrational number       sin⁡15∘cos⁡15∘=12sin⁡30∘=14which is a rational number      sin⁡15∘cos⁡75∘=sin2⁡15∘=12(1−cos⁡30∘)=2−34 which is an irrational number