I. Consider y dened as a function of x by the equation: Ax + By + C = 0 HA, B and C are constants. show that the graph of y is a straight line. What happens when 3:0? E . Note that we say that the focus of the point (x, y) is a straight line. The equation is the general equation of a line on a plane. and is a linear equation. An equation of the form 2 2 (Jr-or) +{y-) = p' is non-linear and represents a circle. Where is its centre? What is its radius? When does 3:2 + y2 +ZGx+ 2Fy+C= 0 represent a circle? This is a non-linear relationship between 3: and x. Can you express 3: in terms of x