Mark M. answered 05/18/19
Retired math prof. Calc 1, 2 and AP Calculus tutoring experience.
Let u = 8x
Then du = (ln8)8xdx.
So, 8xdx = (1/ln8)du
The integral can then be rewritten as (1/ln8)∫cot2udu
= (1/ln8)∫[csc2u - 1]du
= (1/ln8)[-cotu - u) + C
= (1/ln8)[-cot(8x) - 8x) + C
Ariel G.
That is only what is given for the question on my test05/18/19