Question

Particular integral of $y'' + y = \cosh 3x$ is

• A. $\frac{1}{10} \cosh 3x$
• B. $\frac{-1}{10} \sinh 3x$
• C. $3 \cosh x$
• D. $x \sinh 3x$

Hint:

For $\cosh ax$ or $\sinh ax$, substitute $D^2 = a^2$. For $\cos ax$ or $\sin ax$, substitute $D^2 = -a^2$.

Answer 1

The Correct Option is A