Inequality

An inequality is an equation where one side is not necessarily equal, or may not, to the other.

These come in four kinds;

1. An equation which the left hand side is strictly greater than the right denoted <math>></math>
2. An equation which the left hand side is greater than or equal that the right denoted <math>\geq</math>
3. An equation which the left hand side is strictly less than the right denoted <math><</math>
4. An equation which the left hand side is greater than or equal that the right denoted <math>\leq</math>

For example, 4 is greater than 3, so either;

4>3

3<4

are true statements.

The inequalities are wildly used in more advanced mathematics for example the cosine function is always between -1 and 1 inclusive so you can write;

<math>-1\leq\cos x\leq1\; \forall x\in\mathbb{R}</math>.

This gives the function bounds.

See also

• Equation