Some Activities for my first Geogebra Class

(a) The applet below illustrates the Mean Value Theorem, which states that if the function f is continuous on [a,b] and differentiable on (a,b), then there is a number c in (a,b) such that the tangent line at (c,f(c)) is parallel to the line segment AB where A=(a,f(a)) and B=(b,f(b)), i.e.

Use the applet above to find the number c guaranteed by the Mean Value Theorem for the given function and the interval (3,7).

(b) Solve the following problem from the 2005 AMC competition. Solve it where a=20 and b=4. Enter your answer in the box provided.
You can use the tools in the Notes applet below to write, type, and/or attach work.