Advertisements
Advertisements
प्रश्न
Solcve: `x ("d"y)/("d"x) = y(log y – log x + 1)`
Advertisements
उत्तर
Given that: `x ("d"y)/("d"x) = y(log y – log x + 1)`
⇒ `x ("d"y)/("d"x) = y[log(y/x) + 1]`
⇒ `("d"y)/("d"x) = y/x[log(y/x) + 1]`
Since, it is a homogeneous differential equation.
∴ Put y = vx
⇒ `("d"y)/("d"x) = "v" + x * "dv"/"dx"`
∴ `"v" + x * "dv"/"dx" = "vx"/x[log("vx"/x) + 1]`
⇒ `"v" + x * "dv"/"dx" = "v"[log "v" + 1]`
⇒ `x * "dv"/"dx" = "v"[log "v" + 1] - "v"`
⇒ `x * "dv"/"dx"` = v ....[log v + 1 – 1]
⇒ `x * "dv"/"dx" = "v" * log "v"`
⇒ `"dv"/("v"log"v") = "dx"/x`
Integrating both sides, we get
`int "dv"/("v"log"v") = int "dx"/x`
Put log v = t on L.H.S.
`1/"v" "dv"` = dt
∴ `int "dt"/"t" = int "dx"/x`
`log|"t"| = log|x| + log"c"`
⇒ `log|log "v"| = log x"c"`
⇒ log v = xc
⇒ `log(y/x)` = xc
Hence, the required solution is `log(y/x)` = xc.
APPEARS IN
संबंधित प्रश्न
Solve the differential equation (x2 + y2)dx- 2xydy = 0
Show that the differential equation 2yx/y dx + (y − 2x ex/y) dy = 0 is homogeneous. Find the particular solution of this differential equation, given that x = 0 when y = 1.
Show that the differential equation `2xydy/dx=x^2+3y^2` is homogeneous and solve it.
Show that the given differential equation is homogeneous and solve them.
`y' = (x + y)/x`
Show that the given differential equation is homogeneous and solve them.
`x dy/dx - y + x sin (y/x) = 0`
Show that the given differential equation is homogeneous and solve them.
`y dx + x log(y/x)dy - 2x dy = 0`
Show that the given differential equation is homogeneous and solve them.
`(1+e^(x/y))dx + e^(x/y) (1 - x/y)dy = 0`
Which of the following is a homogeneous differential equation?
Prove that x2 – y2 = c (x2 + y2)2 is the general solution of differential equation (x3 – 3x y2) dx = (y3 – 3x2y) dy, where c is a parameter.
Find the particular solution of the differential equation `(x - y) dy/dx = (x + 2y)` given that y = 0 when x = 1.
(x2 + 3xy + y2) dx − x2 dy = 0
Solve the following initial value problem:
\[x e^{y/x} - y + x\frac{dy}{dx} = 0, y\left( e \right) = 0\]
Solve the following initial value problem:
(xy − y2) dx − x2 dy = 0, y(1) = 1
Find the particular solution of the differential equation x cos\[\left( \frac{y}{x} \right)\frac{dy}{dx} = y \cos\left( \frac{y}{x} \right) + x\], given that when x = 1, \[y = \frac{\pi}{4}\]
Show that the family of curves for which \[\frac{dy}{dx} = \frac{x^2 + y^2}{2xy}\], is given by \[x^2 - y^2 = Cx\]
A homogeneous differential equation of the form \[\frac{dx}{dy} = h\left( \frac{x}{y} \right)\] can be solved by making the substitution
Solve the following differential equation : \[\left[ y - x \cos\left( \frac{y}{x} \right) \right]dy + \left[ y \cos\left( \frac{y}{x} \right) - 2x \sin\left( \frac{y}{x} \right) \right]dx = 0\] .
Solve the differential equation: x dy - y dx = `sqrt(x^2 + y^2)dx,` given that y = 0 when x = 1.
Solve the following differential equation:
`"x" sin ("y"/"x") "dy" = ["y" sin ("y"/"x") - "x"] "dx"`
Solve the following differential equation:
`(1 + "e"^("x"/"y"))"dx" + "e"^("x"/"y")(1 - "x"/"y")"dy" = 0`
Solve the following differential equation:
`"y"^2 - "x"^2 "dy"/"dx" = "xy""dy"/"dx"`
Solve the following differential equation:
(9x + 5y) dy + (15x + 11y)dx = 0
Solve the following differential equation:
(x2 + 3xy + y2)dx - x2 dy = 0
Find the equation of a curve passing through `(1, pi/4)` if the slope of the tangent to the curve at any point P(x, y) is `y/x - cos^2 y/x`.
Solve : `x^2 "dy"/"dx"` = x2 + xy + y2.
The solution of the differential equation `(1 + e^(x/y)) dx + e^(x/y) (1 + x/y) dy` = 0 is
The differential equation y' = `y/(x + sqrt(xy))` has general solution given by:
(where C is a constant of integration)
Find the general solution of the differential equation:
(xy – x2) dy = y2 dx
