yes i know, actually got what i think is the derivative and for the problem im working on, I got f'(1) correct but when I plug in 4 for f'(4) it says its incorrect! Error in the system?
What i got was -2/5(x)^(-3/5) - 5/7(8x)^(-2/7)
For f'(1) I got -6.114 and I got that correct
When I got in f' (4) I got -.4395 and it says its incorrect