The parent function for the linear equation is y = x. In general terms, the parent function provides a template for the range and the domain, which holds true for other equations within the family.
Linear equations take their name from their graphic representation, graphing the points that apply to the equation yields a straight line, no matter what the equation. The domain and range for a linear equation extend to all real numbers, and the slope of the equation, also known as the rate of change, remains constant. The exponent for the "x" term in the equation is always 1.