noun. 1  a type of structure of an organism or part of an organism in which a vertical cut through the axis in any of two or more planes produces two halves that are mirror images of each other.2  Compare bilateral symmetry. Trends. 2  a type of structure of an organism or part of an organism in which a vertical cut through the axis in any of two or more planes produces two halves that are mirror images of each other.
There is a standard method for graphing the independent and dependent variable. The x-axis is the independent variable, while the y-axis is the dependent variable. You can use the DRY MIX acronym to help remember how to graph variables: DRY MIX.
Thus, y = f(x) = x^2 means that y, a dependent variable, a function of x, is the square of x. Also, in this form, the expression is called an explicit function of x, contrasted with x^2 - y = 0, which is called an implicit function.