Question

What is the degree of the differential equation, x^3-6x^3 y^3+2xy=0?

(a) 3

(b) 5

(c) 6

(d) 8

I had been asked this question at a job interview.

This is a very interesting question from Non-Homogeneous Linear PDE with Constant Coefficient topic in chapter Partial Differential Equations of Engineering Mathematics

Answer 1

Correct answer is (c) 6

To elaborate: The degree of an equation that has not more than one variable in each term is the exponent of the highest power to which that variable is raised in the equation. But when more than one variable appears in a term, it is necessary to add the exponents of the variables within a term to get the degree of the equation. Hence, the degree of the equation, x^3-6x^3 y^3+2xy=0, is 3+3 = 6.