A man of height 1.5m walks away along a straight line from a lamp post which is 6m high at the rate of 3m/s.Then find
(i)Rate of increase of length of its shadow.
(ii)Rate of change of end of the shadow.

Question

A man of height 1.5m walks away along a straight line from a lamp post which is 6m high at the rate  of 3m/s.Then find
(i)Rate of increase of length of its shadow.
(ii)Rate of change of end of the shadow.

dls · Answer

|dw:1371837573410:dw|
1.5/x=6/y
x=3y..
dx/dt=3y.dy/dt
dx/dt is given 3 
so dy/dt=1
maybe?
not sure about 2nd part though