versin ( θ ) := 2 sin 2 ( θ 2 ) = 1 − cos ⁡ ( θ ) {\displaystyle {\textrm {versin}}(\theta ):=2\sin ^{2}\!\left({\frac {\theta }{2}}\right)=1-\cos(\theta )\,} [3] coversin ( θ ) := versin ( π 2 − θ ) = 1 − sin ⁡ ( θ ) {\displaystyle {\textrm {coversin}}(\theta ):={\textrm {versin}}\!\left({\frac {\pi }{2}}-\theta \right)=1-\sin(\theta )\,} [3] vercosin ( θ ) := 2 cos 2 ( θ 2 ) = 1 + cos ⁡ ( θ ) {\displaystyle {\textrm {vercosin}}(\theta ):=2\cos ^{2}\!\left({\frac {\theta }{2}}\right)=1+\cos(\theta )\,} [19] covercosin ( θ ) := vercosin ( π 2 − θ ) = 1 + sin ⁡ ( θ ) {\displaystyle {\textrm {covercosin}}(\theta ):={\textrm {vercosin}}\!\left({\frac {\pi }{2}}-\theta \right)=1+\sin(\theta )\,} [26] haversin ( θ ) := versin ( θ ) 2 = sin 2 ( θ 2 ) = 1 − cos ⁡ ( θ ) 2 {\displaystyle {\textrm {haversin}}(\theta ):={\frac {{\textrm {versin}}(\theta )}{2}}=\sin ^{2}\!\left({\frac {\theta }{2}}\right)={\frac {1-\cos(\theta )}{2}}\,} [3] hacoversin ( θ ) := coversin ( θ ) 2 = 1 − sin ⁡ ( θ ) 2 {\displaystyle {\textrm {hacoversin}}(\theta ):={\frac {{\textrm {coversin}}(\theta )}{2}}={\frac {1-\sin(\theta )}{2}}\,} [21] havercosin ( θ ) := vercosin ( θ ) 2 = cos 2 ( θ 2 ) = 1 + cos ⁡ ( θ ) 2 {\displaystyle {\textrm {havercosin}}(\theta ):={\frac {{\textrm {vercosin}}(\theta )}{2}}=\cos ^{2}\!\left({\frac {\theta }{2}}\right)={\frac {1+\cos(\theta )}{2}}\,} [33] hacovercosin ( θ ) := covercosin ( θ ) 2 = 1 + sin ⁡ ( θ ) 2 {\displaystyle {\textrm {hacovercosin}}(\theta ):={\frac {{\textrm {covercosin}}(\theta )}{2}}={\frac {1+\sin(\theta )}{2}}\,} [35]