(a + b)2 = a2 + 2ab + b2(a - b)2 = a2 - 2ab + b2:-)
sin A= a/ccos A= b/csin2A + cos2A= 1My love of trigonometry never ends, I apply it in real life as well:)
Ah, the pleasures of the tactile world!
Oh my, I guess I'm too old, not for a new pen but for the things you write with it.
I used to go up and down. Not diagnosed bipolar but I went up and down anyway. When I got way down I would go out and buy a new, and often expensive fountain pen and then I would feel better writing crazy poetry or things like flourished letters of the alphabet. The effects would last a week or two. It was all cured when computers came out and I got into them.
This is actually the least expensive Parker, the Frontier. I got it for 13 Euros at the local office supplies, it was the last one they had. I bought a pot of ink and a rechargable filling with it. I was really bummed when I lost it and couldn't find it for a while and I still had the pot of ink, so I searched the internet for a replacement pen and discovered that i had had it 5 Euro's under the cheapest price they make... in Germany... ex shipping. Fortunately I found it back again. In my car. All packed and ready to go. It has an adventurous spirit.