Asatellite camera takes a rectangular-shaped picture. the smallest region that can be photographed is a 4-km by 4-km rectangle. as the camera zooms out, the length l and width w of the rectangle increase at a rate of 3 km/sec. how long does it take for the area a to be at least 4 times its original size?

So we know that the formula for the area of a rectangle is .
Now both the length and width of the rectangle increase at 3 km/s, therefore, . We want to know the time when the area is four times its original area, therefore, our new formula is: . Plugging in our known values we have:




The area is four times its original area after \frac{4}{3} s" alt="km^2" />. We want to know the time when the area is four times its original area, therefore, our new formula is: . Plugging in our known values we have:




The area is four times its original area after \frac{4}{3} s" />.