Solve y′=1+y2y' = 1 + y^2y′=1+y2 with y(0)=0y(0) = 0y(0)=0. What is the interval of existence?
(−π/2,π/2)(-\pi/2, \pi/2)(−π/2,π/2)
(−∞,∞)(-\infty, \infty)(−∞,∞)
(0,π)(0, \pi)(0,π)
(−1,1)(-1, 1)(−1,1)