Question

alright, attached is the question im having trouble with now....

Answer 1

so far, i know that get the equation of the are of the rectangle, so: A=l times w [l.w] and that i should derive that equation i formed, but im having trouble at this point... not to sure on how to fine the A'. or perhaps am i on the wrong path? o:

Answer 2

It's really hard to measure the rate of change for the area. Lets say one second has passed by. Now we have a w=1 and l=16. Area of that is 16. original area is 60 (5*12) so the area changed by 44/1sec. Now lets say half a second. w=3 l=14. The area of that is 42. The difference is now 18/0.5sec = 36/1sec.

Now the lengths are changing proportional 1gain:1 loss so you can figure out how the rate is changing. Hint: if in every second you gain the same you lose how much are you changing?

Again the diagonals change is not constant. try to measure the change from .5 seconds to 1 second and compare the change in length to the change rate of the area.

Well is the length of the diagonals increasing? well yes but how much?
next i told you the change in area is lowering.

Answer 3

alright, thanks so much, figured it out :]
i got the area decreasing at 44 cm^2/sec
the perimeter is constant
and the diagonals i increasing at a rate of 3cm/sec.