# How to use *Normals* in a sentence

We may therefore regard the nitrogen atoms as occupying the centres of a cubic space lattice composed of iodine atoms, between which the hydrogen atoms are distributed on the tetrahedron face

**normals**.Properties of the limagon may be deduced from its mechanical construction; thus the length of a focal chord is constant and the

**normals**at the extremities of a focal chord intersect on a fixed circle.Apollonius' genius takes its highest flight in Book v., where he treats of

**normals**as minimum and maximum straight lines drawn from given points to the curve (independently of tangent properties), discusses how many**normals**can be drawn from particular points, finds their feet by construction, and gives propositions determining the centre of curvature at any point and leading at once to the Cartesian equation of the evolute of any conic.Leonhard Euler, in his paper on curvature in the Berlin Memoirs for 1760, had considered, not the

**normals**of the surface, but the**normals**of the plane sections through a particular normal, so that the question of the intersection of successive**normals**of the surface had never presented itself to him.In mathematics, the "caustic surfaces" of a given surface are the envelopes of the

**normals**to the surface, or the loci of its centres of principal curvature.AdvertisementSecondary caustics are orthotomic curves having the reflected or refracted rays as

**normals**, and consequently the proper caustic curve, being the envelope of the**normals**, is their evolute.Many well-known derivative curves present themselves in this manner; thus the variable curve may be the normal (or line at right angles to the tangent) at any point of the given curve; the intersection of the consecutive

**normals**is the centre of curvature; and we have the evolute as at once the locus of the centre of curvature and the envelope of the normal.It may be added that the given curve is one of a series of curves, each cutting the several

**normals**at right angles.The fifth book contains properties of

**normals**and their envelopes, thus embracing the germs of the theory of evolutes, and also maxima and minima problems, such as to draw the longest and shortest lines from a given point to a conic; the sixth book is concerned with the similarity of conics; the seventh with complementary chords and conjugate diameters; the eighth book, according to the restoration of Edmund Halley, continues the subject of the preceding book.Perhaps continually pairing spangles to related

**Normals**bred from Spangles somehow weakens the Spangle gene(s) that produce the visual Spangle.AdvertisementLet V i and V2 be the potentials at points just outside and inside the surface dS, and let n l and n 2 be the

**normals**to the surface dS drawn outwards and inwards; then - dV i /dn i and - dV 2 dn 2 are the normal components of the force over the ends of the imaginary small cylinder.But, as originally pointed out by Euler, the difficulty can be turned if we notice that in the ordinary trajectory of practice the quantities i, cos i, and sec i vary so slowly that they may be replaced by their mean values,, t, cos 7 7, and sec r t, especially if the trajectory, when considerable, is divided up in the calculation into arcs of small curvature, the curvature of an arc being defined as the angle between the tangents or

**normals**at the ends of the arc.Perhaps continually pairing Spangles to related

**Normals**bred from Spangles somehow weakens the Spangle gene(s) that produce the visual Spangle.When female patients were compared to agematched

**normals**, greater than one serving per week of grilled (broiled) or baked fish (other than tuna) was associated with a decreased risk of disease.