Question

A circle is inside a square. The radius of the circle is decreasing at a rate of 1 meter per day and the sides of the square are decreasing at a rate of 5 meters per day. When the radius is 5 meters, and the sides are 18 meters, then how fast is the AREA outside the circle but inside the square changing?

Answer 1

z a a = x = side of radius squate of circle Area = A = a ² – TV² a - Tr? (71 - = 2a. - da d+ 2 Tor dr dt همانا 18 = ه ک = = وه - dt dt By putting in DA = 2x 18 (-5) - 2015) () = -180 + dt lo π dA = 148.58 d+ Hence Area region is decreasing of thaald 2 meter per 148. 58