TANGENT n.
or example, the axis of abscissas, or a radius of a circle produced. See Trigonometrical function, under Function. Artificial, or Logarithmic, tangent, the logarithm of the natural tangent of an arc. -- Natural tangent, a decimal expressing the length of the tangent of an arc, the radius being reckoned unity. -- Tang…
TERNARY a.
t parts, as elements, atoms, groups, or radicals, which are regarded as having different functions or relations in the molecule; thus, sodic hydroxide, NaOH, is a ternary compound.
THALLOPHYTA n.
inct tissue systems; the fronds of many algæ, however, are modified to serve many of the functions of the above-named organs. Both asexual and sexual reproduction, often of a complex type, occur in these forms. The Thallophyta exist almost exclusively as gametophytes, the sporophyte being absent or rudimentary. By thos…
THYROID a.
, or Thyroid gland (Anat.), a glandlike but ductless body, or pair of bodies, of unknown function, in the floor of the mouth or the region of the larynx. In man and most mammals it is a highly vascular organ, partly surrounding the base of the larynx and the upper part of the trachea. -- Thyroid dislocation (Surg.), d…
TIDE n.
ccompanied by a high tide upon the opposite side. Hence, when the sun and moon are in conjunction or opposition, as at new moon and full moon, their action is such as to produce a greater than the usual tide, called the spring tide, as represented in the cut. When the moon is in the first or third quarter, the sun's at…
TRIGONOMETRIC; TRIGONOMETRICAL n.
c*al*ly, adv. Trigonometrical curve, a curve one of whose coördinates is a trigonometric function of the other. -- Trigonometrical function. See under Function. -- Trigonometrical lines, lines which are employed in solving the different cases of plane and spherical trigonometry, as sines, tangents, secants, and the l…