 Hello and welcome to the session. The question says, find the derivative of the following functions and it is to be understood that a, b, c, d, p, q, r and s are fixed non-zero constants and m and n are integers. 10th one is, a upon x raised to the power 4 minus b upon x raised to the power 2 plus cos x. So let's start with the solution and let's denote the given function by y. So y is equal to a upon x raised to the power 4 minus b upon x square plus cos x. Now we have to find its derivative that is d by upon dx. So we have d dx of a upon x raised to the power 4 minus b upon x square plus cos x which can further be written as d upon dx of a upon x raised to the power 4 minus d upon dx b upon x square plus d upon dx of cos x. And this is further equal to a is a constant. So taking it outside the derivative we have d upon dx of x raised to the power minus 4 minus. Now taking b outside we have d upon dx of x raised to the power minus 2 plus derivative of cos x is minus sin x. This is further equal to a derivative of x raised to the power minus 4 is minus 4 into x raised to the power minus 5. Since derivative of x raised to the power n is n into x raised to the power n minus 1. and we have minus b, derivative of x raised to the power minus 2 is minus 2 into x raised to the power minus 3 and plus into minus is minus, so we have minus sin x. This is further equal to minus 4a upon x raised to the power 5 minus into minus is plus, so plus 2b upon x cube minus sin x, thus I am differentiating the given function, its derivative is minus 4a upon x raised to the power 5 plus 2b upon x cube minus sin x. So, this completes the session, bye and take care.