Verify that the given function $y - \cos y = x$ is a solution of the differential equation $(y \sin y + \cos y + x) y' = y$.

Vedclass pdf generator app on play store
Vedclass iOS app on app store
(N/A) Given equation: $y - \cos y = x$ ..........$(1)$
Differentiating both sides with respect to $x$:
$\frac{d}{dx}(y) - \frac{d}{dx}(\cos y) = \frac{d}{dx}(x)$
$y' - (-\sin y) y' = 1$
$y'(1 + \sin y) = 1$
$y' = \frac{1}{1 + \sin y}$ ..........$(2)$
Now,consider the $L.H.S.$ of the differential equation:
$L.H.S. = (y \sin y + \cos y + x) y'$
Substitute $x = y - \cos y$ from equation $(1)$:
$L.H.S. = (y \sin y + \cos y + y - \cos y) y'$
$L.H.S. = (y \sin y + y) y'$
$L.H.S. = y(1 + \sin y) y'$
Substitute $y'$ from equation $(2)$:
$L.H.S. = y(1 + \sin y) \cdot \frac{1}{1 + \sin y}$
$L.H.S. = y = R.H.S.$
Since $L.H.S. = R.H.S.$,the given function is indeed a solution of the differential equation.

Explore More

Similar Questions

Let $\frac{dy}{dx} = \frac{ax - by + a}{bx + cy + a}$,where $a, b, c$ are constants,represent a circle passing through the point $(2, 5)$. Then the shortest distance of the point $(11, 6)$ from this circle is

If $\phi(x) = \frac{1}{\sqrt{x}} \int \limits_0^x (4 \sqrt{2} \sin t - 3 \phi^{\prime}(t)) dt, \quad x > 0$,then $\phi^{\prime}\left(\frac{\pi}{4}\right)$ is equal to:

If $y = \frac{x}{\ln |c x|}$ (where $c$ is an arbitrary constant) is the general solution of the differential equation $\frac{dy}{dx} = \frac{y}{x} + \phi \left( \frac{x}{y} \right)$,then the function $\phi \left( \frac{x}{y} \right)$ is:

The solution of $\frac{d^2y}{dx^2} = \cos x - \sin x$ is

If $xdy = y(dx + ydy), y > 0$ and $y(1) = 1,$ then $y(-3)$ is equal to

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo