Graffiti Graffiti Graffiti (both singular and plural; the singular "graffito" is very rare in English except in archeology) is writing or drawings made on a wall or other surface, usually without permission and within public view. Graffiti ranges from simple written words to elaborate wall paintings, and it has existed since ancient times, with examples dating back to ancient Egypt, ancient Greece, and the Roman Empire. In modern times, paint (particularly spray paint) and marker pens have become the most commonly used graffiti materials. In most countries, marking or painting property without the property owner's permission is considered defacement and vandalism,
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