A ladder rests against a wall making an angle `alpha` with the horizontal. The foot of the ladder is
Channel: Doubtnut
Date: 2020-05-09

A ladder rests against a wall making an angle `alpha` with the horizontal. The foot of the ladder is pulled away from the wall through a distance x, so that it  slids a distance y down the wall making an angle `beta` with the horizontal. Then prove that  `x = y tan ((alpha + beta)/(2))`.