Integrating factor of the differential equation cos x(dy/dx) + y sin x = 1,

Question

Integrating factor of the differential equation cos x\(\frac{\text{dy}}{\text{dx}}\) + y sin x = 1, is

A. sin x

B. sec x

C. tan x

D. cos x

Answer 1

Correct answer is B.

cos x(dy/dx) + y sin x = 1

Dividing cos x both sides we get,

The above equation is of the form \(\frac{dy}{dx}+Py=Q\) i.e. linear differential equation.

Here, P = tan x and Q = sec x

Integrating factor = e^{∫ P dx}

Considering ∫ P