Peer Review

This is a very visual tool.  Users have the ability to enter a function.  The tool then displays the graph of the function and an approximated graph of the derivative.  Users can enter the derivative of the function in another box or users can view various available examples in the example box to see if the graph of their derivative matches the approximated graph. Users can also explore the relationship between a derivative and its function by moving the curser along the x-axis to view corresponding points on both graphs.  A link to more information regarding derivatives is included at the top of the page.  Suggestions for exploration are included under the tool. The site includes a disclaimer making it clear that the tool does simple calculations and does not actually know the formula for the derivative of the entered function.  

Some of the figures in the derivative summary information may not be very easy to interpret for users who are just beginning to explore the material.  

There is a slider for a value of “a” at the bottom of the tool which can take on values between 0 and 2.  It is not clear what this value represents.

This would be a great tool for use in in-class demonstrations when introducing derivatives.  The feature allowing users to check the graph of their derivative with the approximated derivative graph could be beneficial to students who are just learning to take derivatives.

When entering functions like sin(x) or ln(x), users must be sure to enter the function using parentheses.  It might be helpful to include a note on how functions should be entered.

This is a great visual tool.  The use of color is helpful. 

There is an advertisement at the bottom of the page, but it is not distracting.