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

1 Answer
Nov 9, 2017

-36/5โˆ’365

Explanation:

Differentiate xy=5, w.r.t

x dy/dt + y dx/dt =0xdydt+ydxdt=0

Now, given x=3, y would be 5/353. Substituting these values dy/dt=4dydt=4 in the expression above,

3 (4) +5/3 dx/dt=03(4)+53dxdt=0

This would give dx/dt= -12 (3/5) = -36/5dxdt=โˆ’12(35)=โˆ’365

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