Let xy=5 and let dy/dt=4. What is dx/dt when x=3 ?

1 Answer
Nov 9, 2017

#-36/5#

Explanation:

Differentiate xy=5, w.r.t

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

Now, given x=3, y would be #5/3#. Substituting these values #dy/dt=4# in the expression above,

#3 (4) +5/3 dx/dt=0#

This would give #dx/dt= -12 (3/5) = -36/5#

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