**Thomas Harriot**(1560-1621)- Born in England.
- He was instrumental in extending and codifying the theory of equations.
- He was the first to use
**>**and**to indicate greater than and less than.**

**Felix Hausdorff**(1862-1942)- Born in Germany.
- He developed the branch of mathematics known as topology.
- He formaulated a maximal principle in general set theory.

**Jacques Herbrand**(1908-1931)- Born in France.
- He formaulated a theory which established a link between quantification theory and sentential logic.

**Charles Hermite**(1822-1901)- Born in France.
- He applied elliptic functions to find solutions of the quintic equation and of LamÃ©’s differential equation..
- He discussed the theory of associated covariants in binary quantics and the theory of ternary quantics

**Heron (Hero of Alexandria)**(fl. 62 CE)- Born in Egypt.
- His formula provides the area of a triangle when the lengths of the three sides are known, but the height is not known.

**David Hilbert**(1862-1943)- Born in Prussia.
- He solved all the known problems of algebraic invariants.
- He introduced sweepng developments and new areas for research in algebraic topography.

**Hipparchus of Rhodes**ca. 180 – ca. 125 BCE)- Born in Greece.
- His mathematical computations to chart the sun, moon, and stars led to his being named the founder of trigonometry.
- He is also considered the founder of Greek astronomy.

**Hippias**(fl. ca.420 BCE)- Born in Greece.
- He invented a curve called the quadratrix, by the means of which an angle can be divided into any given ratio.

**Hippocrates of Chios**(fl. 2nd half of 5th century BCE)- Born in Greece.
- He is credited with the first exposition which developed the theorems of geometry and logically from a few given axioms or postulates, in
*Elements*. - He formulated the quadrature of the lune, that is, the construction of a square having area equal to that of the original plane figure, using only a compass and a straightedge.

**John de Holywood (Sacrobosco)**(ca.1200 – ca.1256)- Born in England.
- His work on arithmetic was a standard authority for many years

**Hypathia**(370-414 CE)- Born in Egypt.
- Very little is known of her work, although it is believed that she was an algebraist.
- She seemed to have had an interest in conic sections.