<Dl> <Dd> cos ⁡ ρ = sin ⁡ φ 1 sin ⁡ φ + cos ⁡ φ 1 cos ⁡ φ cos ⁡ (λ − λ 0) (\ displaystyle \ cos \ rho = \ sin \ varphi _ (1) \ sin \ varphi + \ cos \ varphi _ (1) \ cos \ varphi \ cos \ left (\ lambda - \ lambda _ (0) \ right)) </Dd> </Dl> <Dd> cos ⁡ ρ = sin ⁡ φ 1 sin ⁡ φ + cos ⁡ φ 1 cos ⁡ φ cos ⁡ (λ − λ 0) (\ displaystyle \ cos \ rho = \ sin \ varphi _ (1) \ sin \ varphi + \ cos \ varphi _ (1) \ cos \ varphi \ cos \ left (\ lambda - \ lambda _ (0) \ right)) </Dd> <P> The azimuth from the first to the second point is given by: </P> <Dl> <Dd> tan ⁡ θ = cos ⁡ φ sin ⁡ (λ − λ 0) cos ⁡ φ 1 sin ⁡ φ − sin ⁡ φ 1 cos ⁡ φ cos ⁡ (λ − λ 0) (\ displaystyle \ tan \ theta = (\ frac (\ cos \ varphi \ sin \ left (\ lambda - \ lambda _ (0) \ right)) (\ cos \ varphi _ (1) \ sin \ varphi - \ sin \ varphi _ (1) \ cos \ varphi \ cos \ left (\ lambda - \ lambda _ (0) \ right)))) </Dd> </Dl>

Who is the creator of the polar projection