Let’s talk about what you need to know about linear law in O Level Additional Mathematics.

Basically, in this topic, you are required to convert a relationship between 2 variables to a linear one using linear law rules. You also need to determine the gradient and vertical intercept and from there find the unknown constants.

For instance, if you are given an equation y = ax^{n}, how are you going to plot a linear graph for it? Well, you are definitely not going to plot y against x as you won’t get a straight line graph. Instead, you are going to manipulate the equation. For this scenario, you can take logarithm on both sides of the equation:

For y = ax^{n},

by taking log on both sides,

logy = nlogx + log a

If you were to plot log *y* (vertical axis) against log*x* (horizontal axis), you will get a straight line with n as the gradient and log*a* as the vertical intercept.

As you can see, you also need to know coordinate geometry, particularly that involving equation of a straight line is required.

The O Level Additional Mathematics questions involving linear law are very standard. In my course on linear law (which I called straight-line graphs on Udemy), I show you the 2 types of questions that come out in O Level, and how to approach them. I go through many examples as well so that you can practice, and also reinforce what’s learned. Get our online on-demand course on linear law (straight line graph) and start learning now.

Want to sample the course? Watch our sample video on a typical question on linear law here.

Want a quick summary on linear law? Check out this post here.