Determine your formula for revenue. This is determined by graphing the data over time. It could be seasonally, yearly or in any increment that you choose.
Find the graph of the line using the intercept points and the slope. Use the formula (y2 - y1) / (x2 - x1) to find the slope of the line. Assume that you have an exponential line fit for analysis with calculus in the form of f(x) = x^2 - 2x + 3.
Take the first derivative of the formula; that operation results in the new equation: f ' (x) = 2x - 2. Solve for x in the equation where x = 1.
Evaluate the equation when x is equal to 1: f(1) = 1^2 + 2(1) + 3 = 6. The minimum position of this line is (1, 6).
Take the second derivative of the equation and insert the value 1. If the result is positive, then the line slopes upward and can confirm it is a minimum at (1, 6).
f ' (x) = 2x - 2
f " (x) = 2
f" (1) = 2
The number 2 is positive, so it is confirmed.