Graphical Demonstration of the Derivative of Sine x

Author:
Lew W. S.
Use this applet to investigate and convince yourself the graphical approach to finding the derivative of the function y = sin x
Use the slider to move point P along the y = sin x function and note the gradient of the tangent at that point. A plot of the gradient of the tangent vs the x coordinate of P ie which forms coordinates of new point Q, (by tracing Q as P moves) will reveal that the derivate of sin x is actually cos x. Check this for yourself