This could be a worse day for me if you guys weren’t quick enough to point out the mistakes. Hope I’ll recover soon from bad shape.
I intended to cover more on trigonometric integrals that could be solved by substitution but didn’t find the time to do so. I’m not sure if you noticed, but a big portion of my energy and attention had gone to looking for my erasers and my scribbles (and at times I’m writing from the top of my head, and not copying the right answer I’ve prepared…). That’s a wake-up call for me to really seriously reconsider my lecture set-up to minimize the amount of attention diversion from time to time… Having a messy pile of scribbles definitely will increase my rate of mistakes.
By the way, I have just had my 2nd serious visitor in my office hours (but I’m typing this all alone again…). He helped me realize how useful the widget I posted on the “Tools & tips” section could be.
For example, if you set up the integrals correctly labeling the points of intersection (for Area problems), you could use the equation solver to find the x (or y) coordinates of the points for you! When you’re doing a complicated integration step, the differentiation widget can help you find how much error you have in expression so that you can locate the mistake in minutes or seconds! (Take a look at @153)