I was so excited when I saw that Leibniz was born on 1st July. I have no idea why, but I like the stories about this mathematician, and I enjoy doing Calculus. Also, he is one of those mathematicians even my high-school teacher mentioned, which is a huge plus if you know what I mean.

Gottfried Wilhelm von Leibniz, born on 1st July 1646, was a German polymath and philosopher. Leibniz was the first to see that the coefficients of a system of linear equations could be arranged into an array, now called a matrix, which can be manipulated to find the solution of the system, if any (I enjoy working with matrices and I feel that they are so important everywhere in math, not only when it comes to systems of equations). This method was later called Gaussian elimination. Leibniz’s discoveries of Boolean algebra and of symbolic logic are very important for maths.

Leibniz is credited, along with Sir Isaac Newton, with the discovery of calculus (differential and integral calculus). There are quite some stories with this and there are still some discussion (from time to time) who should be called the “father of calculus”. He introduced several notations used to this day, for instance the integral sign and the ‘d’ used for differentials. The product rule of differential calculus is still called “Leibniz’s law”. In addition, the theorem that tells how and when to differentiate under the integral sign is called the Leibniz integral rule.

But the most important thing he has done ever are the biscuits. The Leibniz-Keks or Choco Leibniz is a German brand of biscuit or cookie produced by the Bahlsen food company since 1891. I find it quite funny and interesting that there is a biscuit brand named after him. It seems that the only connection between the man and the biscuit is that Leibniz was one of the more famous residents of Hanover, where the Bahlsen company is based. At the time when the biscuit was first made there was a fashion of naming food products after historical celebrities

Hope you are all having fun this summer, don’t forget to check my Facebook event: Mathematics and Summer ^_^ Thank you for your help and support. Thank you for reading. You can find me on FacebookTumblr, Google+,  TwitterInstagram and Lettrs, I will try to post there as often as possible. Don’t forget that maths is everywhere! Enjoy!