MCQ
The solution of the differential equation $\frac{d y}{d x}=\sec x-y \tan x$ is .....
  • $y \sec x=\tan x+ c$
  • B
    $y \sec x+\tan x=c$
  • C
    $\sec x=y \tan x+c$
  • D
    $\sec x+y \tan x=c$

Answer

Correct option: A.
$y \sec x=\tan x+ c$
(A)
$\frac{d y}{d x}+y \tan x=\sec x$
The given equation is of the form
$\frac{d y}{d x}+P y=Q$
I. $f==e^{\int P d x}=e^{\int \tan x d x}$
$\begin{aligned} & =e^{\log |\sec x|} \\ & =\sec x\end{aligned}$
Solution of the given equation is
$\begin{aligned} & y \cdot(I \cdot F)=\int Q(I \cdot F) d x+c \\ & y \sec x=\int \sec x \sec x d x+c \\ & y \sec x=\tan x+c\end{aligned}$

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