Calculation: sRSAn0 - 1

 d* sin(φ)  = 
 
 ( 2* k+1)* λ
/ 2
 d* sin(φ) =  
 ( 2* k+1)* λ
/ 2
$$d\cdot sin(\phi)$$ = $$\frac{(2\cdot k+1)\cdot \lambda}{2}$$
 d* sin(φ) =  k* λ+ 
 λ
/ 2
$$d\cdot sin(\phi)$$ = $$k\cdot \lambda+\frac{\lambda}{2}$$
d =  
 ( k* λ+ 
 λ
/ 2
)
/ sin(φ)
$$d$$ = $$\frac{k\cdot \lambda+\frac{\lambda}{2}}{sin(\phi)}$$
d =  
 k* λ
/ sin(φ)
+ 
 0.5* λ
/ sin(φ)
$$d$$ = $$\frac{k\cdot \lambda}{sin(\phi)}+\frac{0.5\cdot \lambda}{sin(\phi)}$$