हिंदी

Given that dydxedydx=e-2x and y = 0 when x = 5. Find the value of x when y = 3.

Advertisements
Advertisements

प्रश्न

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

योग
Advertisements

उत्तर

Given equation is `"dy"/"dx"` = e–2y

⇒ `"dy"/"e"^(-2y)` = dx

⇒ `"e"^(2y) * "d"y` = dx

Integrating both sides, we get

`int "e"^(2y) "d"y = int "d"x`

⇒ `1/2 "e"^(2y)` = x + c

Put y = 0 and x = 5

⇒ `1/2 "e"^0` = 5 + c

⇒ c = `1/2 - 5 = - 9/2`

Now putting y = 3, we get

`1/2 "e"^6 = x - 9/2`

⇒ x = `1/2 "e"^6 + 9/2`

Hence the required value of x =`1/2 ("e"^6 + 9)`.

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 9: Differential Equations - Exercise [पृष्ठ १९३]

APPEARS IN

एनसीईआरटी एक्झांप्लर Mathematics Exemplar [English] Class 12
अध्याय 9 Differential Equations
Exercise | Q 3 | पृष्ठ १९३

वीडियो ट्यूटोरियलVIEW ALL [2]

संबंधित प्रश्न

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


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

 


Verify that y = cx + 2c2 is a solution of the differential equation 

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

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


Differential equation \[\frac{dy}{dx} = y, y\left( 0 \right) = 1\]
Function y = ex


Differential equation \[\frac{d^2 y}{d x^2} + y = 0, y \left( 0 \right) = 1, y' \left( 0 \right) = 1\] Function y = sin x + cos x


\[\sqrt{a + x} dy + x\ dx = 0\]

C' (x) = 2 + 0.15 x ; C(0) = 100


x cos y dy = (xex log x + ex) dx


(ey + 1) cos x dx + ey sin x dy = 0


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

\[\frac{dy}{dx} = 1 - x + y - xy\]

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

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

 


The volume of a spherical balloon being inflated changes at a constant rate. If initially its radius is 3 units and after 3 seconds it is 6 units. Find the radius of the balloon after `t` seconds.


In a culture the bacteria count is 100000. The number is increased by 10% in 2 hours. In how many hours will the count reach 200000, if the rate of growth of bacteria is proportional to the number present.


Find the particular solution of the differential equation
(1 – y2) (1 + log x) dx + 2xy dy = 0, given that y = 0 when x = 1.


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

\[\frac{dy}{dx} + 1 = e^{x + y}\]

3x2 dy = (3xy + y2) dx


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 equation to the curve satisfying x (x + 1) \[\frac{dy}{dx} - y\]  = x (x + 1) and passing through (1, 0).


Find the equation of the curve which passes through the origin and has the slope x + 3y− 1 at any point (x, y) on it.


Radium decomposes at a rate proportional to the quantity of radium present. It is found that in 25 years, approximately 1.1% of a certain quantity of radium has decomposed. Determine approximately how long it will take for one-half of the original amount of  radium to decompose?


The slope of the tangent at each point of a curve is equal to the sum of the coordinates of the point. Find the curve that passes through the origin.


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


In the following verify that the given functions (explicit or implicit) is a solution of the corresponding differential equation:-

`y=sqrt(a^2-x^2)`              `x+y(dy/dx)=0`


Solve the differential equation:

`"x"("dy")/("dx")+"y"=3"x"^2-2`


Choose the correct option from the given alternatives:

The solution of `1/"x" * "dy"/"dx" = tan^-1 "x"` is


Solve the following differential equation.

`y^3 - dy/dx = x dy/dx`


Solve the following differential equation.

xdx + 2y dx = 0


Solve the following differential equation.

`dy/dx + 2xy = x`


The function y = ex is solution  ______ of differential equation


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`


Find the particular solution of the following differential equation

`("d"y)/("d"x)` = e2y cos x, when x = `pi/6`, y = 0.

Solution: The given D.E. is `("d"y)/("d"x)` = e2y cos x

∴ `1/"e"^(2y)  "d"y` = cos x dx

Integrating, we get

`int square  "d"y` = cos x dx

∴ `("e"^(-2y))/(-2)` = sin x + c1

∴ e–2y = – 2sin x – 2c1

∴ `square` = c, where c = – 2c

This is general solution.

When x = `pi/6`, y = 0, we have

`"e"^0 + 2sin  pi/6` = c

∴ c = `square`

∴ particular solution is `square`


Given that `"dy"/"dx"` = yex and x = 0, y = e. Find the value of y when x = 1.


Solve the differential equation `"dy"/"dx"` = 1 + x + y2 + xy2, when y = 0, x = 0.


Solution of `x("d"y)/("d"x) = y + x tan  y/x` is `sin(y/x)` = cx


`d/(dx)(tan^-1  (sqrt(1 + x^2) - 1)/x)` is equal to:


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×