The tutor offers a hint about using the Nexus 4 onboard calculator for sin, cos, and tan. One of my New Year’s resolutions is to get acquainted with my mobile phone. Believe it or not, I’ve been lounging on the …

Mobile phone apps: Nexus 4 onboard calculator: trig functions Read more »

The tutor delves deeper into when integer solutions can be expected for Ax+By=C. In my dec 16 post I discussed finding integer coordinates for a linear equation in the form Ax+By=C. I pointed out that not always can integer solutions …

Math: linear diophantine equations: integer solutions to Ax+By=C Read more »

The tutor offers proof of a formula he recalls from Stats. In my university Stats courses, a formula referred to often was V(X)=E(X^2)-(E(X))^2 in which V(X)=population variance E(X^2)=expected value of X^2 E(X)=expected value of X Here’s how I believe one …

Statistics: Proof of V(X)=E(X²)-[E(X)]² Read more »

Amid a busy life and Bitdefender’s solid reliability, it wins again. Coincidentally, on this first day of Christmas break, my Bitdefender 2015 subscription finally expired. Back in my Dec 6 post, I told of plans to get out to check …

Home computer use: Computer security: Bitdefender re-install Read more »