Monday, May 02, 2005
Sometimes I love when at the last minute I get this "light bulb idea" about how to teach a particular topic. That happened today with my precalculus class's first exposure to a derivative. We've been working on limits and left and right limits and then moved on to the calculating of the slope of the tangent line to a curve, and today, Aha. Instead of just telling them the standard "shortcut" form of derivative for f(x) = ax^n ...... I had each group use the formal definition of derivative to calculate it for f(x) = ax^2 + b for various a's and b's, then as a class we looked at all the derivatives, and they saw the pattern. Yea. Tomorrow we'll do 3rd power and also maybe one ax^2 + bx + c one and we'll be off.