Example Find the equation of the line that goes through the points (−1, 3) and (3, 11). Sketch the two points and join them with a straight line.

This line will pass through the circle at a second point, and it turns out this other intersection also has to be a rational point. Some algebra will show us why. Since the line has slope 2 and y ...

The straight line through two points will have an equation in the form \(y = mx + c\). We can find the value of \(m\), the gradient of the line, by forming a right-angled triangle using the ...