Final answer:
The difference quotient is used to calculate the derivative at a point, slope of a secant line, and average rate of change. It is an application of the first principles of calculus.
Step-by-step explanation:
The difference quotient is used to calculate the derivative of a function at a point. It represents the slope of a secant line between two points on the function.
To find the difference quotient, choose two points on the function and substitute their x-values into the function. Then, calculate the change in y-values and divide it by the change in x-values. This will give you the slope of the secant line and the average rate of change between the two points.
The difference quotient is an application of the first principles of calculus, which involve finding the instantaneous rate of change using limits.