The length l of a rectangle is decrasing at a rate of 2 cm/sec while the width w is increasing at a rate of 4 cm/sec. When l = 14 cm and w = 9 cm, find the following rates of change:

The rate of change of the diagonals:

Question

The length l of a rectangle is decrasing at a rate of 2 cm/sec while the width w is increasing at a rate of 4 cm/sec. When l = 14 cm and w = 9 cm, find the following rates of change: 

The rate of change of the diagonals:

anonymous · Answer

I get 1/2(14*9)^(-1/2)*(-2*9+14*4)... can't find my error...

handsomechickenlover · Answer

118 I believe. But, I could be way way off. So, don't think this answer this answer could be 100%. mayde 50% or 30%.

anonymous · Answer

Nope isn't 118! Thanks though :-) I cant find my error either, doesn't seem like a hard problem but I did something wrong

radar · Answer

I come up with the rate of change of the diagonal as .48 cm/sec.  Is this one of the options?

radar · Answer

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