## Tuesday, September 24, 2013

### Derivatives of Exponentials and Logs with Desmos

Here's a Desmos activity I typed up for my calc kids to find the the derivatives of exponential and logarithmic functions.  Sadly...the class set of laptops would not connect to the domain because they hadn't been used all summer, so we did this together as a class, which was not what I wanted, but what can you do?  Instead of having the kids click pause on their own screens, I had them yell "STOP" at me...so it was still entertaining.

All this to say, I don't know if this is good or not since I haven't gotten to test it out on students yet, but here it is.  Use/modify if you'd like!

In the "notice/wonder" section of f(x)=a^x, one student said he noticed that the derivative was proportional to the given function.  This made me a very proud momma and was a perfect segue into finding the derivative when a is different from e.  (We explored f(x)=2^x, f'(x), and g(x)=lna(2^x), and found that a=2).

Desmos also sent me this great online activity.