a ladder 10m long is leaning against a vertical wall with its other end on the ground. the top end of the ladder is sliding down the wall , when the top end is 6m from the ground it is sliding down at 2m/sec. how fast is the bottom moving away from the wall at this instant?

Answer 1

x^2+y^2 = 10^2
so, when x=6, y=8

2x dx/dt + 2y dy/dt = 0

Now just plug in your values to find dx/dt

Answer 2

-3/2