Advertisements
Advertisements
Question
Solve : `x^2 "dy"/"dx"` = x2 + xy + y2.
Advertisements
Solution
Given equation is `x^2 "dy"/"dx"` = x2 + xy + y2
⇒ `"dy"/"dx" = (x^2 + xy + y^2)/x^2`
Put y = vx ......[∵ it is a homogeneous differential equation]
∴ `"dy"/"dx" = "v" + x * "dv"/"dx"`
∴ `"v" + x * "dv"/"dx" = (x^2 + "v"x^2 + "v"^2x^2)/x^2`
⇒ `"v" + x * "dv"/"dx" = (x^2(1 + "v" + v"^2))/x^2`
⇒ `"v" + x * "dv"/"dx" = 1 + "v" + "v"^2`
⇒ `x * "dv"/"dx" = 1 + "v" + "v"^2 - "v"`
⇒ `x * "dv"/"dx" = 1 + "v"^2`
⇒ `"dv"/(1 + "v"^2) = "dx"/x`
Integrating both sides, we get
`int "dv"/(1 + "v"^2) = int "dx"/x`
⇒ tan–1v = log x + c
⇒ `tan^-1 (y/x)` = log x + c
Hence, the required solution is `tan^-1 (y/x)` = log |x| + c.
APPEARS IN
RELATED QUESTIONS
Solve the differential equation (x2 + y2)dx- 2xydy = 0
Find the particular solution of the differential equation:
2y ex/y dx + (y - 2x ex/y) dy = 0 given that x = 0 when y = 1.
Show that the given differential equation is homogeneous and solve them.
(x – y) dy – (x + y) dx = 0
Show that the given differential equation is homogeneous and solve them.
`x dy - y dx = sqrt(x^2 + y^2) dx`
For the differential equation find a particular solution satisfying the given condition:
x2 dy + (xy + y2) dx = 0; y = 1 when x = 1
For the differential equation find a particular solution satisfying the given condition:
`[xsin^2(y/x - y)] dx + x dy = 0; y = pi/4 "when" x = 1`
For the differential equation find a particular solution satisfying the given condition:
`2xy + y^2 - 2x^2 dy/dx = 0; y = 2` when x = 1
A homogeneous differential equation of the from `dx/dy = h (x/y)` can be solved by making the substitution.
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.
(x2 − 2xy) dy + (x2 − 3xy + 2y2) dx = 0
(x2 + 3xy + y2) dx − x2 dy = 0
Solve the following initial value problem:
(x2 + y2) dx = 2xy dy, y (1) = 0
Solve the following initial value problem:
(xy − y2) dx − x2 dy = 0, y(1) = 1
Solve the differential equation: ` (dy)/(dx) = (x + y )/ (x - y )`
Solve the following differential equation:
`(1 + 2"e"^("x"/"y")) + 2"e"^("x"/"y")(1 - "x"/"y") "dy"/"dx" = 0`
Solve the following differential equation:
`"y"^2 - "x"^2 "dy"/"dx" = "xy""dy"/"dx"`
Solve the following differential equation:
`x^2. dy/dx = x^2 + xy + y^2`
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`.
Which of the following is not a homogeneous function of x and y.
F(x, y) = `(ycos(y/x) + x)/(xcos(y/x))` is not a homogeneous function.
The solution of the differential equation `(1 + e^(x/y)) dx + e^(x/y) (1 + x/y) dy` = 0 is
A homogeneous differential equation of the `(dx)/(dy) = h(x/y)` can be solved by making the substitution.
The differential equation y' = `y/(x + sqrt(xy))` has general solution given by:
(where C is a constant of integration)
The solution of the differential equation y2 dx + (x2 − xy + y2)dy = 0 is ______.
