French mathematician Adrien-Marie Legendre was born #OTD in 1752.
He he studied physics in Paris & later taught at a military academy because he liked to teach and not because he needed the money. Well-known and important concepts such as the Legendre polynomials & Legendre transformation are named after him. He is also known for his contributions to the method of least squares, & was the first to officially publish on it, though Carl Friedrich Gauss had discovered it before him.