Question

What is the order of the differential equation given by \(\frac{dy}{dx} + 4y = sin x\)?

(a) 0.5

(b) 1

(c) 2

(d) 0

This question was addressed to me during an interview for a job.

This interesting question is from First Order First Degree Differential Equations topic in portion Ordinary Differential Equations – First Order & First Degree of Engineering Mathematics

Answer 1

The correct choice is (b) 1

To explain I would say: Since the order of a differential equation is defined as the order of the highest derivative occurring in the differential equation, i.e for nth derivative \(\frac{d^ny}{dx^n}\) if n=1.

It has order 1\(\rightarrow\) differential equation contains only \(\frac{dy}{dx}\) derivative with variables and constants.