## 5800 Reputation

16 years, 57 days

## Using Maple to outsmart google...

Maple

It appears google doesn't know about the haversine formula.  Huh?  Well at least google can't draw the proper path for it.  I typed in google "distance from Pyongyang to NewYork city"  and got 10,916km.  Ok that's fine but then it drew a map

The map path definitely did not look right.  Pulled out my globe traced a rough path of the one google showed and I got 13 inches (where 1 inch=660miles) -> 8580 miles = 13808 km .. clearly looks like google goofed.

So we need Maple to show us the proper path.

```with(DataSets):
with(Builtin):
m := WorldMap();
Display(m):
```

Ok so you say that really doesn't look like the shortest path.  Well, lets visualize that on the globe projection

`Display(m, projection = Globe, orientation = [-180, 0, 0])`

Ah, now it is clear
Pyonyang_to_NewYork.mw

## Star database procedure query of Simbad...

Maple

Here's a little procedure to fish out data from the Simbad database.  Some star names may not work if the page Simbad brings up is not completely filled, but it should work for most queries.

 (1)

 (2)

 (3)

 (4)

## Main Stars within 50 ly...

Maple

I found this http://www.atlasoftheuniverse.com/50lys.html and wondered how to do it in Maple. With a bit of data file editing I came up with this.  All stars within 50 light years that are visible to the naked eye.

 (1)

 (2)

The modified data file and the maple worksheet below

stars3.txt

## Realizing measurements from a sheet of p...

Ever needed to measure something and all you had was a piece of paper?  This leads us to how we can use maple to figure out what we can measure using a sheet of standard 8-1/2" x 11" paper.

Can we measure 6" with a sheet of paper?

```> eq := (17/2)*x+11*y = 6;
17
eq := -- x + 11 y = 6
2
> eq2 := isolve(eq, a);
eq2 := {x = -20 - 22 a, y = 16 + 17 a}
> subs(a = 0, b = 0, eq2);
{x = -20, y = 16}
```

So that is the simplest case, stacking up 16 pieces on the long side and subtracting 20 on the short side.  A total of toppling the piece of paper over 36 times.  That's a high percentage of of error.

But wait!  haha.   Wouldn't a fold make it simpler?  Sure!  Fold the 8.5" across and we now have 2.5" to work with.

```> eq := (17/2)*x+11*y+(5/2)*z = 6;
17            5
eq := -- x + 11 y + - z = 6
2             2
> eq2 := isolve(eq, {a, b});
eq2 := {x = a, y = 1 + 4 a + 5 b, z = -2 - 21 a - 22 b}
> subs(a = 0, b = 0, eq2);
{x = 0, y = 1, z = -2}
```

Less toppling of pieces of paper and much less error.

## Can not copy paste in mapleprimes ...

MaplePrimes

The copy paste and snip tool used to work.  I can no longer use either to paste in mapleprimes.

 4 5 6 7 8 9 10 Last Page 6 of 38
﻿