Question
Choose the correct answer from the given four option.
Integrating factor of the differential equation $\cos\frac{\text{d}\text{y}}{\text{d}\text{x}}+\text{y}\sin\text{x}=1$ is:
  1. $\cos\text{x}$
  2. $\tan\text{x}$
  3. $\sec\text{x}$
  4. $\sin\text{x}$

Answer

  1. $\sec\text{x}$

Solution:

we have, $\cos\frac{\text{d}\text{y}}{\text{d}\text{x}}+\text{y}\sin\text{x}=1$

$\Rightarrow\frac{\text{d}\text{y}}{\text{d}\text{x}}+\text{y}\tan\text{x}=\sec\text{x}$

This is a linear differential equation.

On comparing it with $\frac{\text{d}\text{y}}{\text{d}\text{x}}+\text{P}\text{y}=\text{Q},$ we get

$\text{P}=\tan\text{x}$ and $\text{Q}=\sec\text{x}$

$\text{I.F.}=\text{e}^{\int\text{Pdx}}=\text{e}^{\int\tan\text{xdx}}$

$=\text{e}^{\log\sec\text{x}}=\sec\text{x}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Let $\text{y}=\sqrt{\sin\text{x}+\text{y}},$ then $\frac{\text{dy}}{\text{dx}}=$
  1. $\frac{\sin\text{x}}{2\text{y}-1}$
  2. $\frac{\sin\text{x}}{1-2\text{y}}$
  3. $\frac{\cos\text{x}}{1-2\text{y}}$
  4. $\frac{\cos\text{x}}{2\text{y}-1}$
The differential equation of the family of parabolas with focus at the origin and the $x$-axis as axis is
$\int \frac{1-\cos x}{1+\cos x} d x=$ __________  + C .
For $a \in R$ (the set of all real numbers), $a \neq-1, \lim _{n \rightarrow \infty} \frac{\left(1^a+2^a+\ldots+n^a\right)}{(n+1)^{a-1}[(n a+1)+(n a+2)+\ldots+(n a+n)]}=\frac{1}{60}$. Then $a=$

$(A)$ $5$ $(B)$ $7$ $(C)$ $\frac{-15}{2}$ $(D)$ $\frac{-17}{2}$

The order of the differential equation  ${{{y\left( \frac{dy}{dx} \right)=x}/{\frac{dy}{dx}+\left( \frac{dy}{dx} \right)}\;}^{3}}$  is
If $A=\left[\begin{array}{rr}\cos \alpha & -\sin \alpha \\ \sin \alpha & \cos \alpha\end{array}\right]$ and $A+A^{\prime}=I$, then the value of $\alpha$ is
For $m, n > 0$, let $\alpha(m, n)=\int_0^2 t^m(1+3 t)^n d t$. If $11 \alpha(10,6)+18 \alpha(11,5)= p (14)^6$, then $p$ is equal to $......$.
If $A, B, C$ are the angles of a triangle and $\left| {\begin{array}{*{20}{c}}1&1&1\\{1 + \sin A}&{1 + \sin B}&{1 + \sin C}\\{\sin A + {{\sin }^2}A}&{\sin B + {{\sin }^2}B}&{\sin C + {{\sin }^2}C} \end{array}} \right|$ $= 0$, then the triangle is

If the mean and variance of a binomial distribution are 4 and 3, respectively, the probability of getting exactly six successes in this distribution is:

  1. $\text{ }^{16}\text{C}_6\big(\frac{1}{4}\big)^{10}\big(\frac{3}{4}\big)^6$

  2. $\text{ }^{16}\text{C}_6\big(\frac{1}{4}\big)^{6}\big(\frac{3}{4}\big)^{10}$

  3. $\text{ }^{12}\text{C}_6\big(\frac{1}{20}\big)\big(\frac{3}{4}\big)^6$

  4. $\text{ }^{12}\text{C}_6\big(\frac{1}{20}\big)^6\big(\frac{3}{4}\big)^6$

The diameter of one of the bases of a truncated cone is $100\,mm$. If the diameter of this base is increased by $21 \%$ such that it still remains a truncated cone with the height and the other base unchanged, the volume also increases by $21 \%$. The radius of the other base (in $mm$ ) is