Which one of the following is the correct expression for the versine (h) of a curve ?(Where l = length of rail on the curve portion and r = radius of curvature)

Which one of the following is the correct expression for the versine (

1.	Which one of the following is the correct expression for the versine (h) of a curve ?(Where l = length of rail on the curve portion and r = radius of curvature)
A.	<img src="/_files/images/civil-engineering/upsc-civil-service-exam-questions/34-1365-1.png">
B.	<img src="/_files/images/civil-engineering/upsc-civil-service-exam-questions/34-1365-2.png">
C.	<img src="/_files/images/civil-engineering/upsc-civil-service-exam-questions/34-1365-3.png">
D.	<img src="/_files/images/civil-engineering/upsc-civil-service-exam-questions/34-1365-4.png">
Answer» D. <img src="/_files/images/civil-engineering/upsc-civil-service-exam-questions/34-1365-4.png">