Question

What are linear functions?

Answer 1

A linear function is a function in which the variable x can appear with exponent of 0 or 1 at maximum.
The general form of a linear function is:
y=ax+b
Where a and b are real numbers.
The graph of a linear function is a straight line.

"a" is called slope or gradient and representes the change in y for each change of unity in x. For example, a=5 means that every time x increases of 1, y increases of 5 (in case of "a" negative, y decreases).
"b" representes the point where the line crosses the y axis.

For example, consider: