Tigni

Tigni n uzunglay.

Deg tenzeggit, Tigni neɣ Tizwi d akat n tuẓẓma n twinest neɣ n tuzza. Ma d tigni n kra n umtiweg iga d tizzungeltis. Tuzza tla (tesɛa) tigni n 0, ma d tagra timifedg usdid ila tigni n 1.

Amtiweg amazzay ila amili agaman i wemsel neɣ i tigni,Asemdu n webralmas isselfaw-d tamerruzt tasbegsant.
S tusnak, tigni tettwafek-d s:

$f=\text{ver}(o\epsilon )=2{\sin }^2\left(\frac{o\epsilon }{2}\right)=1-\cos (o\epsilon )=\frac{a-b}{a}\approx \frac{15\pi }{4G{T}^2\rho };$

anda $a$ d $b$ gan d izenzaren n waggad d usafaylu n umtiweg, s umdafar, d $o\epsilon$ iga d ’aɣwali uɣmir. Tamawaẓt d taɣbelt deg tegʷnit n umtiweg amengi seg tneẓẓi tayiwnit, dɣa tga d tasɣent n imezgi aldayan aseddayan, $G$, n tallit n tuzzya $T$ yakk n tneẓẓi $\rho$.
Akken i tella daɣen tigni tis snat, f' (tikwal tettwasezmel « n ») :

$f^{\prime }={\tan }^2\left(\frac{o\epsilon }{2}\right)=\frac{1-\cos (o\epsilon )}{1+\cos (o\epsilon )}=\frac{a-b}{a+b}$.