An expression is a combination of numbers, variables, and operators that represents a value. Examples include arithmetic expressions like 3 + 4 × 5, and algebraic expressions such as 2x + 3.
You can use standard operator precedence, and also call JavaScript’s Math functions (for example, Math.sin(Math.PI/2) or Math.sqrt(16)).
This app allows you to evaluate expressions directly and even graph functions of one variable for a visual understanding.