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.[br]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)[br]will reveal that the derivate of sin x is actually cos x.[br]Check this for yourself