Analyzing Concave Down Segments of the Sinusoidal Curve

Hi Andrius,

Here is a detailed approach you can use:

1. Get the data points details
   1. Manually extract data points if you have the coordinates.
   2. Digitize the chart to get coordinates, if needed.
   3. For each curve, create a data set with x and y coordinates.
2. Define the model function
   1. Use curve fitting to model/fit each section of the graph based on the extracted data points in previous step.
   2. For example, you can use the following model functions in general:
      1. Sinusoidal Curve: $y=aSin⁡(bx+c)+d$
      2. Parabolic Curve: $y=ax^{2} +bx+c$
3. Fit the model to the data
   1. Use Python or R to fit models to your data
4. Plot the data and the fitted curve
   1. Plot the fitted curve to check visually and make sure the process worked as it should.
   2. If the fitted curves don't look good, go back to Steps 1-3 and repeat.
5. Calculate curvature at the vertex
   1. Calculate the curvature of a curve using its formulas for k
6. Calculate the distance between A and B
   1. Calculate the distance between two points using its formula