For hundreds of years many have attempted to prove Newton's Parallelogram Law of Forces but could not come up with a completely satisfactory one. Recently a Bangladeshi mathematician, Professor Ahmed Shibli Forkan, has proven the law by using projection, vector dot product and cosine rule. Since the 17th century, Parallelogram Law of Forces -- a method for solving the results of applying two forces to an object -- remained unproven though it was taken for granted as true.
While writing a book on math, Professor Forkan, Head of Mathematics Department at Dhaka College (retired), encountered the theorem and tried to solve it. Without any expectation he tried one method after another and eventually came up with a proof using vector dot products. “I proved the theorem in 2011. Then I applied another method, and a reverse method to check whether my finding was accurate,” said the mathematician.
“Then I sent my paper to different authorities abroad who deal with these types of issues so that they could scrutinize my proof and recognise it. Some of them replied, others did not, but I continued my effort. Then I sent my paper to WASET -- World Academy of Science Engineering and Technology. They accepted my paper and invited me to the conference to give a presentation on it. I attended the conference that took place on June 5-6, 2013 and received a certificate from WASET,” Professor Forkan said.
He published a booklet, titled “Proof of Parallelogram Law of Forces” after WASET recognised his proof. The proof could help students understand the method perfectly. He proved the theorem in four ways and included them in his book. He sent the printed books to many institutions. He also included in the book the certificate he received from WASET. Professor Forkan's inquisitive nature led him to prove Newton's theorem. “I always try to solve problems in more than one way and like to experiment with new things,” he said.
Professor Forkan's future plan is to write more books on mathematics which students would find helpful. Though writing a book is a difficult task and requires a lot of effort, he wants to stay committed. His aspiration is to achieve the highest honour in the field of mathematics. In the process, he will surely make Bangladesh proud.