How Old Is the Decimal System and the Discoverion of Trigonometry in India?

How old is the decimal system and discovery of trigonometry, etc. in India? Where did it happen? Very interesting question. Aravata wrote about it, you know, in his book. He called it an ancient knowledge. It is very, very difficult to pinpoint when it was invented. And this is where I feel strongly that India must attract their best brains to work in this field. We do not know our own heritage."