English

If y = e–x (Acosx + Bsinx), then y is a solution of ______. - Mathematics

Advertisements
Advertisements

Question

If y = e–x (Acosx + Bsinx), then y is a solution of ______.

Options

  • `("d"^2y)/("d"x^2) + 2("d"y)/("d"x)` = 0

  • `("d"^2y)/("d"x^2) - 2 ("d"y)/("d"x) + 2y ` = 0

  • `("d"^2y)/("d"x^2) + 2 ("d"y)/("d"x) + 2y` = 0

  • `("d"^2y)/("d"x^2) + 2y` = 0

MCQ
Fill in the Blanks
Advertisements

Solution

If y = e–x (Acosx + Bsinx), then y is a solution of `("d"^2y)/("d"x^2) + 2 ("d"y)/("d"x) + 2y` = 0.

Explanation:

Given equation is y = e–x (Acosx + Bsinx)

Differentiating both sides, w.r.t. x, we get

 `("d"y)/("d"x)` = e–x (–A sin x + B cos x) – e–x (A cos x + B sin x)

`("d"y)/("d"x)` = e–x (–A sin x + B cos x) – y

Again differentiating w.r.t. x, we get

`("d"^2y)/("d"x^2) = "e"^-x (-"A" cos x - "B" sin x) - "e"^-x (-"A" sinx + "B"cosx) - ("d"y)/("d"x)`  

⇒ `("d"^2y)/("d"x^2) = -"e"^-x ("A" cosx + "B" sinx) - [("d"y)/("d"x) + y] - ("d"y)/("d"x)`

⇒ `("d"^2y)/("d"x^2) = - y - ("d"y)/("d"x) - y - ("d"y)/("d"x)`

⇒ `("d"^2y)/("d"x^2) = - 2 ("d"y)/("d"x) - 2y`

⇒ `("d"^2y)/("d"x^2) + 2("d"y)/("d"x) + 2y` = 0

shaalaa.com
  Is there an error in this question or solution?
Chapter 9: Differential Equations - Exercise [Page 195]

APPEARS IN

NCERT Exemplar Mathematics [English] Class 12
Chapter 9 Differential Equations
Exercise | Q 37 | Page 195

RELATED QUESTIONS

Solve the differential equation cos(x +y) dy = dx hence find the particular solution for x = 0 and y = 0.


Find the particular solution of the differential equation

(1 – y2) (1 + log x) dx + 2xy dy = 0, given that y = 0 when x = 1.


Solve the differential equation `dy/dx -y =e^x`


Verify that the given function (explicit or implicit) is a solution of the corresponding differential equation:

y = Ax : xy′ = y (x ≠ 0)


The number of arbitrary constants in the particular solution of a differential equation of third order are ______.


Solve the differential equation `[e^(-2sqrtx)/sqrtx - y/sqrtx] dx/dy = 1 (x != 0).`


Find a particular solution of the differential equation`(x + 1) dy/dx = 2e^(-y) - 1`, given that y = 0 when x = 0.


Find the particular solution of the differential equation

`tan x * (dy)/(dx) = 2x tan x + x^2 - y`; `(tan x != 0)` given that y = 0 when `x = pi/2`


The population of a town grows at the rate of 10% per year. Using differential equation, find how long will it take for the population to grow 4 times.


The solution of the differential equation \[2x\frac{dy}{dx} - y = 3\] represents


The solution of x2 + y \[\frac{dy}{dx}\]= 4, is


Find the particular solution of the differential equation `(1+y^2)+(x-e^(tan-1 )y)dy/dx=` given that y = 0 when x = 1.

 

The solution of the differential equation \[\frac{dy}{dx} = \frac{y}{x} + \frac{\phi\left( \frac{y}{x} \right)}{\phi'\left( \frac{y}{x} \right)}\] is


(x + y − 1) dy = (x + y) dx


(1 + y + x2 y) dx + (x + x3) dy = 0


x2 dy + (x2 − xy + y2) dx = 0


\[x\frac{dy}{dx} + x \cos^2 \left( \frac{y}{x} \right) = y\]


\[\cos^2 x\frac{dy}{dx} + y = \tan x\]


`(dy)/(dx)+ y tan x = x^n cos x, n ne− 1`


For the following differential equation, find the general solution:- \[\frac{dy}{dx} = \sin^{- 1} x\]


For the following differential equation, find a particular solution satisfying the given condition:- \[\cos\left( \frac{dy}{dx} \right) = a, y = 1\text{ when }x = 0\]


Solve the following differential equation:-

\[x\frac{dy}{dx} + 2y = x^2 , x \neq 0\]


Solve the following differential equation:-

\[\frac{dy}{dx} + 2y = \sin x\]


Solve the following differential equation:-

\[\frac{dy}{dx} + \frac{y}{x} = x^2\]


Solve the following differential equation:-

\[x\frac{dy}{dx} + 2y = x^2 \log x\]


The solution of the differential equation `x "dt"/"dx" + 2y` = x2 is ______.


The general solution of the differential equation x(1 + y2)dx + y(1 + x2)dy = 0 is (1 + x2)(1 + y2) = k.


y = x is a particular solution of the differential equation `("d"^2y)/("d"x^2) - x^2 "dy"/"dx" + xy` = x.


Find the general solution of `"dy"/"dx" + "a"y` = emx 


Find the general solution of the differential equation `(1 + y^2) + (x - "e"^(tan - 1y)) "dy"/"dx"` = 0.


Solve:

`2(y + 3) - xy  (dy)/(dx)` = 0, given that y(1) = – 2.


Find the general solution of `("d"y)/("d"x) -3y = sin2x`


The solution of `("d"y)/("d"x) + y = "e"^-x`, y(0) = 0 is ______.


The solution of `x ("d"y)/("d"x) + y` = ex is ______.


The solution of `("d"y)/("d"x) + y = "e"^-x`, y(0) = 0 is ______.


The general solution of the differential equation (ex + 1) ydy = (y + 1) exdx is ______.


The solution of the differential equation `x(dy)/("d"x) + 2y = x^2` is ______.


The solution of `("d"y)/("d"x) = (y/x)^(1/3)` is `y^(2/3) - x^(2/3)` = c.


Find a particular solution, satisfying the condition `(dy)/(dx) = y tan x ; y = 1` when `x = 0`


Find the general solution of the differential equation:

`log((dy)/(dx)) = ax + by`.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×