The derivative of the sine function

Daryl Funk
Move the slider or input values for a. The blue curve is the graph of y=sin(x), and the red line is the tangent to the curve at the point (a, sin(a)). Recall that the slope of the tangent line to the curve at (a,f(a)) is the value f'(a). The red point is the point (a, f'(a)). Notice that the graph of y=d/dx(sin(x)) is cos(x).