Differential Equations — Class 12 Maths Solution

exemplar objective MCQ NCERT EXEMP.Q.40,Page.196
Question

The integrating factor of differential equation $\cos x\frac{{dy}}{{dx}} + y\sin x = 1$ is

  • (a) $\cos x$
  • (b) $\tan x$
  • (c) $\sec x$ ✓ Correct
  • (d) $\sin x$
Step-by-step Solution
Correct answer: option (c)

Given that, $\cos x\frac{{dy}}{{dx}} + y\sin x = 1$

$\Rightarrow$ $\frac{{dy}}{{dx}} + y\tan x = \sec x$

Here, $P = \tan x$ and $Q = \sec x$

$IF = {e^{\int P dx}} = {e^{\int {\tan } xdx}} = {e^{\log \sec x}}$

$\therefore$ $= \sec x$

NCERT & Exemplar solution for CBSE Class 12 Mathematics, Differential Equations. Curated by Sachin Sharma. Free for all students.