Answer:
[tex]\large\boxed{\sin180^o=0\ and\ \cos180^o=-1}[/tex]
Step-by-step explanation:
[tex]\text{Use}\\sin(2\theta)=2\sin\theta\cos\theta\\\\\cos(2\theta)=\cos^2\theta-\sin^2\theta\\\\180^o=2(90^o)\\\\\sin90^o=1\\\\\cos90^o=0\\===================\\\\\sin180^o=\sin(2\cdot90^o)=2\sin90^o\cos90^o=2(1)(0)=0\\\\\cos180^o=\cos(2\cdot90^o)=\cos^290^o-\sin^290^o=0^2-1^2=-1[/tex]
