Compute dy/dx using the chain rule.
y = (u/4) + (4/u)
u = (x - x^7)
dy/dx =
well, just plug and chug
dy/dx = dy/du * du/dx
= (1/4 - 4/u^2)(1 - 7x^6)
= 1/4 (1-16/(x-x^7)^2)(1-7x^6)
and you can massage that as you like
y = (u/4) + (4/u)
u = (x - x^7)
dy/dx =
dy/dx = dy/du * du/dx
= (1/4 - 4/u^2)(1 - 7x^6)
= 1/4 (1-16/(x-x^7)^2)(1-7x^6)
and you can massage that as you like