English

D Y D X + 2 X = E 3 X

Advertisements
Advertisements

Question

\[\frac{dy}{dx} + 2x = e^{3x}\]
Advertisements

Solution

We have, 
\[\frac{dy}{dx} + 2x = e^{3x} \]
\[ \Rightarrow \frac{dy}{dx} = e^{3x} - 2x\]
\[ \Rightarrow dy = \left( e^{3x} - 2x \right)dx\]
Integrating both sides, we get
\[ \Rightarrow \int dy = \int\left( e^{3x} - 2x \right)dx\]
\[ \Rightarrow y = \frac{e^{3x}}{3} - 2\frac{x^2}{2} + C\]
\[ \Rightarrow y = \frac{e^{3x}}{3} - x^2 + C\]
\[ \Rightarrow y + x^2 = \frac{e^{3x}}{3} + C\]
\[So, y + x^2 = \frac{e^{3x}}{3} + \text{ C is defined for all }x \in R . \]
\[\text{ Hence,} y + x^2 = \frac{e^{3x}}{3} +\text{ C, where } x \in R,\text{ is the solution to the given differential equation }.\]

shaalaa.com
  Is there an error in this question or solution?
Chapter 21: Differential Equations - Exercise 22.05 [Page 34]

APPEARS IN

R.D. Sharma Mathematics Volume 1 and 2 [English] Class 12
Chapter 21 Differential Equations
Exercise 22.05 | Q 3 | Page 34

RELATED QUESTIONS

Form the differential equation of the family of hyperbolas having foci on x-axis and centre at the origin.


Show that the function y = A cos x + B sin x is a solution of the differential equation \[\frac{d^2 y}{d x^2} + y = 0\]


Show that y = AeBx is a solution of the differential equation

\[\frac{d^2 y}{d x^2} = \frac{1}{y} \left( \frac{dy}{dx} \right)^2\]

Show that y = ax3 + bx2 + c is a solution of the differential equation \[\frac{d^3 y}{d x^3} = 6a\].

 


Verify that y = − x − 1 is a solution of the differential equation (y − x) dy − (y2 − x2) dx = 0.


Verify that \[y = e^{m \cos^{- 1} x}\] satisfies the differential equation \[\left( 1 - x^2 \right)\frac{d^2 y}{d x^2} - x\frac{dy}{dx} - m^2 y = 0\]


\[\frac{dy}{dx} = \tan^{- 1} x\]


\[\frac{1}{x}\frac{dy}{dx} = \tan^{- 1} x, x \neq 0\]

\[\cos x\frac{dy}{dx} - \cos 2x = \cos 3x\]

\[x\frac{dy}{dx} + 1 = 0 ; y \left( - 1 \right) = 0\]

\[x\left( x^2 - 1 \right)\frac{dy}{dx} = 1, y\left( 2 \right) = 0\]

\[\frac{dy}{dx} = \frac{1 + y^2}{y^3}\]

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

\[\sqrt{1 + x^2 + y^2 + x^2 y^2} + xy\frac{dy}{dx} = 0\]

Solve the following differential equation:
\[xy\frac{dy}{dx} = 1 + x + y + xy\]

 


Find the particular solution of edy/dx = x + 1, given that y = 3, when x = 0.


Find the particular solution of the differential equation \[\frac{dy}{dx} = - 4x y^2\]  given that y = 1, when x = 0.


In a bank principal increases at the rate of 5% per year. An amount of Rs 1000 is deposited with this bank, how much will it worth after 10 years (e0.5 = 1.648).


\[\frac{dy}{dx}\cos\left( x - y \right) = 1\]

\[\cos^2 \left( x - 2y \right) = 1 - 2\frac{dy}{dx}\]

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

\[\left( x + y + 1 \right)\frac{dy}{dx} = 1\]

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

 

The population of a city increases at a rate proportional to the number of inhabitants present at any time t. If the population of the city was 200000 in 1990 and 250000 in 2000, what will be the population in 2010?


In a simple circuit of resistance R, self inductance L and voltage E, the current `i` at any time `t` is given by L \[\frac{di}{dt}\]+ R i = E. If E is constant and initially no current passes through the circuit, prove that \[i = \frac{E}{R}\left\{ 1 - e^{- \left( R/L \right)t} \right\}.\]


The decay rate of radium at any time t is proportional to its mass at that time. Find the time when the mass will be halved of its initial mass.


Find the curve for which the intercept cut-off by a tangent on x-axis is equal to four times the ordinate of the point of contact.

 

At every point on a curve the slope is the sum of the abscissa and the product of the ordinate and the abscissa, and the curve passes through (0, 1). Find the equation of the curve.


The slope of a curve at each of its points is equal to the square of the abscissa of the point. Find the particular curve through the point (−1, 1).


Integrating factor of the differential equation cos \[x\frac{dy}{dx} + y \sin x = 1\], is


The integrating factor of the differential equation \[\left( 1 - y^2 \right)\frac{dx}{dy} + yx = ay\left( - 1 < y < 1 \right)\] is ______.


Form the differential equation from the relation x2 + 4y2 = 4b2


Solve the following differential equation.

`dy/dx = x^2 y + y`


For each of the following differential equations find the particular solution.

`y (1 + logx)dx/dy - x log x = 0`,

when x=e, y = e2.


Choose the correct alternative.

The differential equation of y = `k_1 + k_2/x` is


The solution of `dy/dx + x^2/y^2 = 0` is ______


Solve:

(x + y) dy = a2 dx


Verify y = `a + b/x` is solution of `x(d^2y)/(dx^2) + 2 (dy)/(dx)` = 0

y = `a + b/x`

`(dy)/(dx) = square`

`(d^2y)/(dx^2) = square`

Consider `x(d^2y)/(dx^2) + 2(dy)/(dx)`

= `x square + 2 square`

= `square`

Hence y = `a + b/x` is solution of `square`


Given that `"dy"/"dx" = "e"^-2x` and y = 0 when x = 5. Find the value of x when y = 3.


The value of `dy/dx` if y = |x – 1| + |x – 4| at x = 3 is ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×