Resposta :
Olá, Franklin.
[tex]\sin \frac{ \pi }{2} =\sin 90\º = 1 \\\\ \cos \frac{ \pi }{2} =\cos 90\º = 0 \\\\ \tan \frac{ \pi }{2} =\tan 90\º =\frac {\sin 90\º}{\cos 90\º}=\frac10=\infty \\\\ \text{Resposta: letra "A"}[/tex]
[tex]\sin \frac{ \pi }{2} =\sin 90\º = 1 \\\\ \cos \frac{ \pi }{2} =\cos 90\º = 0 \\\\ \tan \frac{ \pi }{2} =\tan 90\º =\frac {\sin 90\º}{\cos 90\º}=\frac10=\infty \\\\ \text{Resposta: letra "A"}[/tex]