How do you differentiate #f(x)=sec(4x^5)#?

1 Answer
Aug 13, 2017

#d/(dx) [sec(4x^5)] = color(blue)(20x^4tan(4x^5)sec(4x^5)#

Explanation:

We're asked to find the derivative

#d/(dx) [sec(4x^5)]#

We can first use the chain rule:

#d/(dx) [sec(4x^5)] = d/(du) [secu] (du)/(dx)#

where

  • #u = 4x^5#

  • #d/(du) [secu] = tanusecu#:

#= tan(4x^5)sec(4x^5)d/(dx) [4x^5]#

We now use the power rule:

#d/(dx)[x^n] = nx^(n-1)#

where #n = 5#:

#= tan(4x^5)sec(4x^5)5(4x^4)#

#color(blue)(ulbar(|stackrel(" ")(" "20x^4tan(4x^5)sec(4x^5)" ")|)#