Differential equations mistaken as terrorist script

I am sure you heard of this interesting news about a woman thought the professor sitting next to her on a flight is scribbling terrorist script as he was working on some math (differential) equation. See here.

It is unfortunate that the actual equation being worked on is not shown on any news media... perhaps that hand handwritten math was kinda hard to read... it is perfectly fine only the guy working with it can read it... but mistaken as terrorist scripts? It must be really sloppy. Or that lady's math ability is really limited.

Ok, differential equation is no beginner stuff. That ordinary dy/dx derivative notation is already difficult for many people... You can blame Leibniz on that... perhaps f'(x) is better. The professor is probably doing some elaborate partial derivative things with that cursive d which make it more terrifying to look at.

This stuff is really beyond my math ability. I have only seen some very basic ordinary ones and yes I forgot all of it, even though I have taken a "C" or "300" level course on it. All I remember is if something fall in a certain form you can use some specific solving tricks.

Children tale on money

While reading a children's book about money for fun I discovered this fairly tale bank:

Ooh where can you find 5% interest nowadays? Today a savings account is more like 0.1% interest. Come on kids, do that division... just how small is this interest rate now? You don't get 5% even on a Certificate of Deposit for 10 years with $100,000.

Now once upon a time... that interest rate WAS true. The author is not entirely lying.

Why the heck interest is SO low these days? That means: got to invest and risk losing or leave it there to see your money evaporate in inflation. Good luck.

Is there ay children's book about this incredibly low interest nowadays?

for-looping dates

Thanks to self-less people in StackOverflow... learned another new trick.. looping through java.util.Date. http://stackoverflow.com/questions/4534924/how-to-iterate-through-range-of-dates-in-java. No I don't use java 8. If you let people use lambda stuff they go crazy with it.

SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
Date startDate = formatter.parse("2010-12-20");
Date endDate = formatter.parse("2010-12-26");

Calendar start = Calendar.getInstance();
start.setTime(startDate);
Calendar end = Calendar.getInstance();
end.setTime(endDate);

for (Date date = start.getTime(); start.before(end); 
    start.add(Calendar.DATE, 1), 
    date = start.getTime()) {

    // Do your job here with `date`.
    System.out.println(date);
}

..and yes, Java pre-8 date handling is incredibly clumsy. Can't do anything unless you put it into a Calendar. Why can't java.util.Date have the ability to do that?

Indiana clears path for Trump

Indiana primary ended. Cruz still don't win. Drops out. Cruz + Carly didn't work either. The other guy who has even less support than Cruz dropped out too. No more obstacles for Trump. He is the Republican nominee. Despite all that insulting remarks Trump make... He still wins. There are genuinely people, lots of them, who believe he can make America great again.

As I long predicted... it would be Trump vs Hillary and Hillary would eventually win. She had her issues but clearly better choice than Trump.

A "viral" math problem

http://www.davidwolfe.com/answer-viral-math-problem-japan/

Uh hem, what's so viral about this? What's so hard about this? All elementary school students should be able to do this... Order of Operations is defined exactly to avoid ambiguity. Only 60% Japanese people can do this? That's pretty low.

What about Americans?

When you have an arithmetic expression to evaluate you don't go for the calculator first. You see if you can do it in-your-head first. 3 ÷ 1/3? Flip that 1/3 and multiply (divide fraction means multiply by its reciprocal). Ok it is 9. 9-9. boom. gone. Answer is 1.