2- for the initial valhue problem d = y + cost, existence of its solution given that r is the rectangle containing origin, v(0) = 0, determine the interval of r

2- For the initial valhue problem d = y + cost, existence of its solution given that R is the rectangle containing origin, v(0) = 0, determine the interval of R: {(z,v):0S * 1/2,b> 0.