my website

hyperbola

A curve shaped like an arch.

The distances of any point on a hyperbola from ...

... a fixed point (the focus), and ...
... a fixed straight line (the directrix) ...

... are always in the same ratio.

It is one of the "Conic Sections"

.line segment

Part of a line connecting two points.

It has definite end points.

The word "segment" is important, because a line normally extends in both directions without end.

Pi

The ratio of a circle's circumference to its diameter

Equal to 3.14159265358979323846... (the digits go on forever without repeating)

A rough approximation is 22/7 (=3.1428571...), but that is not very accurate

Ramanujan was born on 22 December 1887 in the city Erode, Tamil Nadu, India, at the residence of his maternal grandparents. His father, K. Srinivasa Iyengar worked as a clerk in a sari shop and hailed from the district of Thanjavur. His mother, Komalatammal or Komal Ammal was a housewife and also sang at a local temple. They lived in Sarangapani Street in a traditional home in the town of Kumbakonam. The family home is now a museum. When Ramanujan was a year and a half old, his mother gave birth to a son named Sadagopan, who died less than three months later. In December 1889, Ramanujan had smallpox and recovered, unlike thousands in the Thanjavur district who succumbed to the disease that year. He moved with his mother to her parents’ house in Kanchipuram, near Madras (now Chennai). In November 1891, and again in 1894, his mother gave birth, but both children died in infancy.