 Hi and welcome to the session. Let us discuss the following question. Question says, determine order and degree of the following differential equation. Given differential equation is, d square y upon dx square is equal to cos 3x plus sin 3x. Let us now start with the solution. Now we have given differential equation d square y upon dx square is equal to cos 3x plus sin 3x. Now first of all we will find order of this differential equation. Now we know order of a differential equation is the order of the highest order derivative occurring in the differential equation. Now we know this is the highest order derivative occurring in this differential equation. So order of this differential equation is 2. So we can write the highest order derivative present in the given differential equation is d square y upon dx square. So its order is 2. Now let us find out degree of this differential equation. Now we know degree of a differential equation is defined if it is a polynomial equation in its derivatives. Now clearly we can see this is a polynomial equation in d square y upon dx square. So degree of this differential equation is defined. Now we know degree of a differential equation is the highest power of the highest order derivative present in it. This is the highest order derivative present in this equation and its power is 1. So degree of this given differential equation is 1. Now we can write given differential equation is a polynomial equation in d square y upon dx square. And the highest power raised to d square y upon dx square is 1. So its degree is 1. Now we get order of the given differential equation is 2 and degree of the given differential equation is 1. This is our required answer. This completes the session. Hope you understood the solution. Take care and keep smiling.