What is an affine function?
An affine function, also known as first degree polynomial function, is a function of f : ℝ→ℝ, defined as the form y=ax+b or f(x) = ax + b, where a and b are real numbers and a ≠ 0, b ≠ 0.
In this type of functions the a is called the coefficient of x and represents the growth rate, variation rate or angular coefficient. The b is called the constant term and represents the y-interception.
How to plot the graph of y = x + 3?
To plot the graph, one needs to know at least two points. The graph of an affine function is a straight line that intercepts the y-axis in the point (0, b).
It is necessary to calculate the root (or zero) of the function. The root, or zero, is where the function intercepts the x-axis, and can be calculated equalizing y=0.
x + 3 = 0 -> x = -3
The two points to plot the graph will be:
And the graph will look something like:
