Question

Find the derivative of sin5x.cos7x

Answer 1

Answer:

Step-by-step explanation:

let

y=sin5x.cos7x

differenciating on both side with respect to x

dy/dx=d(sin7x.cos7x)/dx

          =[{cos7x*d(sin7x)/dx}+{sin7x*dcos7x/dx|}]

          =cos7x*(dsin7x/d7x)*d7x/dx+sin7x*(dcos7x/d7x)*d7x/dx

          =cos7x*cos7x*7+sin7x*(-sin7x)*7

          =7[(cosx)^2-(sinx)^2]

          =7(cos14x)

∴d(sin5x.cos7x)/dx=7cos14x