bilateral symmetry the configuration of an irregularly shaped body (such as the human body or that of higher animals) that can be divided by a longitudinal plane into halves that are mirror images of each other. radial symmetry that in which the body parts are arranged regularly around a central axis.he configuration of an irregularly shaped body (such as the body of a higher animal) that can be divided by a longitudinal plane into halves that are mirror images of each other. radial symmetry. that in which the body parts are arranged regularly around a central axis.
Linear Functions. If the power of both x and y in a relation is one, then the relation is called a linear relation or linear function. For example, y = 3x + 5, 7x  8y = 56 and 2x + 3y + 6 = 0 are linear functions because the power of both x and y is one. Plotting Graphs of Linear Functions.
Definition of a Linear Function. A linear function is any function that graphs to a straight line. What this means mathematically is that the function has either one or two variables with no exponents or powers. If the function has more variables, the variables must be constants or known variables for the function to remain a linear function.