sin ⁡ π 2 = sin ⁡ 90 ∘ = 1 {\displaystyle \sin {\frac {\pi }{2}}=\sin 90^{\circ }=1\,} cos ⁡ π 2 = cos ⁡ 90 ∘ = 0 {\displaystyle \cos {\frac {\pi }{2}}=\cos 90^{\circ }=0\,} tan ⁡ π 2 = tan ⁡ 90 ∘ is undefined {\displaystyle \tan {\frac {\pi }{2}}=\tan 90^{\circ }{\text{ is undefined}}\,} cot ⁡ π 2 = cot ⁡ 90 ∘ = 0 {\displaystyle \cot {\frac {\pi }{2}}=\cot 90^{\circ }=0\,}