What is a function - A function of the form y = mx+c, where m and c are constants, is called a linear function. The graph of a linear function is a straight line which cuts the y-axis at ( 0, c ).
Eg. y = 2x +1 is a linear function.
What is the relationship between x and y? - if two variables x and y vary in such a way that each value of x corresponds to one and only one value of y, then y is said to be a function x.
Is function a relationship? - Yes, function is a relationship between X and Y. And either X or Y is dependent on the other variable.