In the context of simple circular curve, which of the following is correct equation for mid-ordinate? (where, R = radius of curve, Δ = deflection angle)
1
\(\rm M=R\left(1-\cos \frac{\Delta}{2}\right)\)
2
\(\mathrm{M}=\mathrm{R}\left(1+\cos \frac{\Delta}{2}\right)\)
3
\(\mathrm{M}=\mathrm{R}\left(\cos \frac{\Delta}{2}\right)\)
4
\(M=R\left(1-\sin \frac{\Delta}{2}\right)\)