A one-parameter family of solutions of the fi­rst-order differential equation dy/dx = xy^1/2 is y = (1/4 x⁴ + c)² for c ≥ 0. Each solution in this family is de­ned on (-∞, ∞). The last statement is not true if we choose c to be negative. For c = -1, explain why y = (1/4x⁴ – 1)² is not a solution of the DE on the interval (-∞, ∞). Find an interval of de­nition I on which y = (1/4 x⁴ – 1)² is a solution of the DE.