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

## فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

### M. Heydari-Malayeri    -    Paris Observatory

Homepage

Number of Results: 11 Search : differential equation
 differential equation   هموگش ِ دگرسانه‌ای   hamugeš-e degarsâneyiFr.: équation différentielle   An equation expressing a relationship between an → independent variable, x, an unknown → function, y = f(x), and its → derivatives. The general form of a differential equation is: F(x, y, y', y'', ..., y(n)) = 0, or F(x,y, dy/dx, d2y/dx2, ..., dny/dxn) = 0. See also: → ordinary differential equation; → partial differential equation; → linear differential equation; → exact differential equation; → first-order differential equation; → homogeneous linear differential equation; → nonhomogeneous linear differential equation; → differential equation with separated variables; → differential equation with separable variables.→ differential; → equation. differential equation with separable variables   هموگش ِ دگرسانه‌ای با ورتنده‌های ِ جدایی-پذیر   hamugeš-e degarsâne-yi bâ vartandehhâ-ye jodâyi-pazirFr.: équation différentielle à variables séparables   A → differential equation of the form: M1(x) N1(y) dx + M2(x) N2(y) dy = 0, which can be reduced to a → differential equation with separated variables. → differential; → equation; → separate; → variable. differential equation with separated variables   هموگش ِ دگرسانه‌ای با ورتنده‌های ِ جدا   hamugeš-e degarsâne-yi bâ vartandehhâ-ye jodâFr.: équation différentielle à variables séparées   A → differentail equation that can be transformed into the form: M(x)dx + N(x)dy = 0. → differential; → equation; → separate; → variable. 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.