Gradient of a Curve

This applet illustrates the basics of differential calculus. Drag point B to move the tangent. a is the number of x^5, b is the number of x^4, c is the number of x^3, d is the number of x^2, e is the number of x, f is the constant. Drag the sliders to change these values. The number below point B is the x-coordinate, and the number to the right is the y-coordinate. (Bear in mind that these numbers do not go negative when point B is dragged across to the negative side of either axis, so please mentally add a minus sign in) The orange triangle shows the gradient of the tangent.