How do you differentiate f(x)=cot5x * cot3x using the product rule?

1 Answer
Jul 24, 2016

(df)/(dx)=-3cot5xcsc^2 3x-5cot3xcsc^2 5x

Explanation:

According to product rule, if f(x)=g(x)xxh(x)

(df)/(dx)=g(x)xx(dh)/(dx)+(dg)/(dx)xxh(x)

Here as g(x)=cot5x and h(x)=cot3x, hence

(df)/(dx)=cot5x xx-csc^2 3x xx3+(-csc^2 5x xx5xxcot3x)

= -3cot5xcsc^2 3x-5cot3xcsc^2 5x