Posted by **Mulan** on Tuesday, November 3, 2009 at 9:43pm.

1)Suppose Q = x^3 y^2 . If [dQ/dt] = −1 and [dx/dt] = 2, find [dy/dt] when

x = 4 and y = 5 .

[dy/dt] =______

2)Let A be the area of a circle with radius r. If [ dr / dt ] = 2, find [ dA / dt ] when r = 3

- Calculus -
**bobpursley**, Tuesday, November 3, 2009 at 9:46pm
I will do one, and be happy to check your thinking.

q=x^3 y^2

dq/dt= 2x^2 y dy/dt+ 3y^2x^2 dx/dt

put in dq/dt, dx/dt, and find dy/dt ..

- Calculus -
**Mulan**, Tuesday, November 3, 2009 at 9:52pm
i dont get it..

dq/dt isnt it 3x^2y

and i don't get the part where you put 3y^2x^2 how many exponents are there

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