Plotting an inequality example (video) | Khan Academy 2) An open circle means you start at the number -1 but you do not include it in the solution A closed circle means you start at -1 and it is included as part of the solution
Introduction to piecewise functions - Khan Academy A closed circle means "Also includes this point" (like <= >=) A good way to remember is that an open circle ( ) is not colored in so the point it is on is NOT included