Calculus
posted by Reonea .
A 18 ft ladder leans against a wall. The bottom of the ladder is 4 ft from the wall at time t=0 and slides away from the wall at a rate of 3ft/sec.
Find the velocity of the top of the ladder at time t=1.
The velocity of ladder at time t=1 is __________ ft/sec.

look at the triangle.
c^2=b^2+h^2 b= base, h=height
take derivitave
d c^2/dt=0=2bdb/dt + 2h dh/dt
b=4, db/dt=3ft/sec h=sqrt(18^24^2)
find dh/dt