Numerical equations are those statements of equality that contain only numbers, like 2+3=5. But there are many other kinds of equations throughout the study of mathematics. Some of the most important are linear and quadratic and polynomial equations in algebra, differential equations in calculus and Cartesian equations in geometry.
A linear equation is the simplest equation in algebra. Each term in the statement of equality is either a constant number or the product of a constant number and one variable, and each term is only to the power of one. An example of a linear equation is 9x=72. A quadratic equation is a statement with a variable to the second power: for example, x² + 2x ? 8 = 0.
Cartesian equations are used in geometry to locate points on objects in space. These equations use two numbers that are called the x-coordinate and the y-coordinate. These two coordinates are plotted on the surface of a graph. Cartesian equations are named after the great French mathematician and philosopher who made important discoveries in algebraic geometry in the 17th century.
Differential equations, based on “derivatives,” deal with motion and change. These equations are used in science and engineering, as well as in economics.