Mean Value Theorem:
There exists c in [a,b] such that f'(c)=[ f(b) - f(a) ] / [ b - a ].
Slide c along the x-axis to match the slope of the secant line.
Slide a,b to change the secant line.
To explore further, enter a new function in the Input field, e.g., f(x)=cos(x).