Guess the derivative function

Catch the point P and move it back and forth to see how the slope changes The red dots show the value of the slope. The points makes a track that shows the contours of the derivative function. Guess the derivative function and write it in f '(x) If you want to delete the track, press the button 'Clear You can try other functions by changing f (x) Example given: f(x)=cos(x) If you want to change the axes write new values ​​in xMin, yMin, xMax, yMax