James B. answered 03/28/23
Tutor
New to Wyzant
B.S. in Math with 2+ years tutoring experience
d/dx(x^(-7)) = -7x^(-8) by the chain rule
d/dx(e^(-8x)) = -8e^(-8x) also by the chain rule, notably that d/dx (-8x) = -8 and d/dx(e^(x)) = e^(x)
thus
d/dx(x^(-7) + e^(-8x)) = -7x^(-8) - 8e^(-8x)