Inequality Calculator

An inequality is solved much like an equation, except that multiplying or dividing by a negative turns the sign round. Pick one of four shapes and give the numbers: a linear inequality with x on both sides, a quadratic against zero, an absolute value against a number, or a compound band with x trapped in the middle. You get the solution written as an inequality and in interval notation, the steps including every sign change, the boundary points, and the number line described in words as open or filled circles with the shaded side named. Cases with no solution and cases where every real number works are called out rather than left blank, which covers a quadratic with no real roots or an absolute value set against a negative. It works from the coefficients you enter, so it cannot read a typed expression, and it does not do two variables, systems, or a variable in a denominator.