# An Etymological Dictionary of Astronomy and AstrophysicsEnglish-French-Persian

## فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

### M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 31 Search : different
 differentiation   دگرسانش   degarsânešFr.: (Math.) dériver; (Astro.) différenciation   1) Math.: The operation of finding the → derivative of a function. 2) Astro.: Process by which an originally homogeneous planetary or asteroidal body is separated into regions of different composition, such as core, mantle, and crust.Verbal noun of → differentiate. exact differential   دگرسانه‌ی ِ رزین   degarsâne-ye razinFr.: différentielle exacte   If N(x,y) is a → function of two → independent variables, then dN = (∂N/∂x)dx + (∂N/∂y)dy is the exact differential.→ exact; → differential. exact differential equation   هموگش ِ دگرسانه‌ای ِ رزین   hamugeš-e degarsâneyi-ye razinFr.: équation différentielle exacte   A → differential equation composed of → continuous  → differentiable functions for which certain conditions are fulfilled. The equation M(x,y)dx + N(x,y)dy = 0 is called exact if M(x,y) and N(x,y) are continuous differentiable functions for which the following relationship is fulfilled: ∂M/∂y = ∂N/∂x, and ∂M/∂y and ∂N/∂x are continuous in some region.→ exact; → differential; → equation. first-order differential equation   هموگش ِ دگرسانه‌ای ِ رایه‌ی ِ نخست   hamugeš-e degarsâne-yi-ye râye-ye naxostFr.: équation différentielle du premier ordre   A → differential equation containing only the first → derivative. For example, dy/dx = 3x and 2y(dy/dx) + 3x = 5.→ first; → order; → differential; → equation. homogeneous linear differential equation   هموگش ِ دگرسانه‌ای ِ خطی همگن   hamugeš-e degarsâne-yi-ye xatti hamgenFr.: équation différentielle linéaire homogène   A → linear differential equation if the right-hand member is zero, Q(x) = 0, on interval I.→ homogeneous; → linear; → differential; → equation. linear differential equation   هموگش ِ دگرسانه‌ای ِ خطی   hamugeš-e degarsâne-yi-ye xattiFr.: équation différentielle linéaire   An equation in which the → dependent variable y and all its differential coefficients occur only in the first degree. A linear differential equation of → order  order n has the form: fn(x)y(n) + fn-1(x)y(n-1) + ... + f1(x)y' + f0(x)y = Q(x), where f0(x), f1(x), ..., fn(x) and Q(x) are each continuous functions of x defined on a common interval I and fn(x)≠ 0 in I. A linear differential equation cannot have, for example, terms such as y2 or (y')1/2. See also: → homogeneous linear differential equation; → nonhomogeneous linear differential equation.→ linear; → differential; → equation. linearized differential equation   هموگش ِ دگرسانه‌ای ِ خطی   hamugeš-e degarsâneyi-ye xattiFr.: équation différentielle linéarisée   A differential equation that has been derived from an original nonlinear equation.Linearized, p.p. of → linearize; → differential; → equation. nonhomogeneous linear differential equation   هموگش ِ دگرسانه‌ای ِ خطی ناهمگن   hamugeš-e degarsâne-yi-ye xatti nâhamgenFr.: équation différentielle linéaire non homogène   A → linear differential equation if Q(x)≠ 0 on interval I.→ nonhomogeneous; → linear; → differential; → equation. ordinary differential equation   هموگش ِ دگرسانه‌ای شونیک   hamugeš-e degarsâneyi-ye šunikFr.: équation différentielle ordinaire   A → differential equation in which the unknown function depends on only one → independent variable, as contrasted with a → partial differential equation.→ ordinary; → differential; → equation. partial differential equation   هموگش ِ دگرسانه‌ای با واخنه‌ی ِ پاری   hamugeš-e degarsâne-yi bâ vâxane-ye pâriFr.: équation différentielle aux dérivées partielles   A type of differential equation involving an unknown function (or functions) of several independent variables and its (or their) partial derivatives with respect to those variables.→ partial; → differential; → equation. undifferentiated meteorite   شهاب‌سنگ ِ نا-دگرسانیده   šahâbsang-e nâdegarsânidéFr.: météorite indifférenciée   A type of meteorite in which the constituting materials (stone, glass, metal) are mixed together in a disorderly mass, in contrast to → differentiated meteorites.→ un-; → differentiated meteorite.

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