Graffiti it is a rapidly developing art form whose value is highly contested and reviled by many authorities while also subject to protection, sometimes within the same jurisdiction. Both "graffiti" and its occasional singular form "graffito" are from the Italian word "graffiato" ("scratched"). "Graffiti" is applied in art history to works of art produced by scratching a design into a surface. A related term is "sgraffito", which involves scratching through one layer of pigment to reveal another beneath it. This technique was primarily used by potters who would glaze their wares and then scratch a design into it. In ancient times
Singular solution uniqueness if a solution of the first form intersects the second solution. The condition of intersection is : "y"("x") = "y"("x"). We solve to find the intersection point, which is formula_41. We can verify that the curves are tangent at this point "y'"("x") = "y'"("x"). We calculate the derivatives: Hence, is tangent to every member of the one-parameter family of solutions of this Clairaut equation: Singular solution A singular solution "y"("x") of an ordinary differential equation is a solution that is singular or one for which the initial value problem (also called the Cauchy problem by some authors) fails to