Question

If the I.F. of the differential equation $\frac{dy}{dx}+5y=\cos x$ is $\int e^{Adx}$, then $A=$

• A. 0
• B. 1
• C. 3
• D. 5

Answer 1

Answer: (D)

The I.F. of the differential equation
$\frac{dy}{dx}+Py=Q$ is $e^{\int Pdx}.$
Here $P=5$
therefore $I.F.=e^{\int 5dx}.$
Hence $A=5$.