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Trigonometric Functions (table)

(Encyclopedia)Trigonometric Functions

quadratic

(Encyclopedia)quadratic, mathematical expression of the second degree in one or more unknowns (see polynomial). The general quadratic in one unknown has the form ax2+bx+c, where a, b, and c are constants and x is t...

hydrocarbon

(Encyclopedia)hydrocarbon hīˌdrōkärˈbən [key], any organic compound composed solely of the elements hydrogen and carbon. The hydrocarbons differ both in the total number of carbon and hydrogen atoms in their ...

Kuhn, Richard

(Encyclopedia)Kuhn, Richard rĭkhˈärt ko͞on [key], 1900–1967, Austrian chemist, director of the Kaiser Wilhelm Institute, Heidelberg. For his research on the carotinoids (he prepared eight of them in pure form...

Marggraf, Andreas Sigismund

(Encyclopedia)Marggraf, Andreas Sigismund ändrāˈäs zēˈgĭsmo͝ont märkˈgräfˌ [key], 1709–82, German chemist, a pioneer in analytical chemistry. He proved that alumina, magnesia, and lime are distinct ea...

N

(Encyclopedia)N, 14th letter of the alphabet. It is a usual symbol for a voiced alveolar (or dental) nasal, as in the English not. The diagraph ng represents a different sound, a voiced velar nasal, as in the Engli...

Hilgard, Eugene Woldemar

(Encyclopedia)Hilgard, Eugene Woldemar hĭlˈgärd [key], 1833–1916, American agricultural chemist and geologist, Ph.D. Univ. of Heidelberg, 1853. Born in Germany, he was brought to the United States in 1836. An ...

Heyrovsky, Jaroslav

(Encyclopedia)Heyrovsky, Jaroslav, 1890–1967, Czech chemist, Ph.D. Charles Univ. of Prague, 1918; D.Sc. University College, London, 1921. Heyrovsky was director of the Polarography Institute at the Czechoslovak A...

H

(Encyclopedia)H, 8th letter of the alphabet. It is a usual symbol for a glottal spirant, murmured (as in the English house) or voiceless (as in the English herb). In some Greek alphabets eta, the long e, had this f...

Franck, James

(Encyclopedia)Franck, James frängk [key], 1882–1964, German physicist. He was professor of physics at Göttingen and at Johns Hopkins (1935–38) and professor of physical chemistry at the Univ. of Chicago from ...