Question

if y=tan u , u=v-1÷v, and v=ln x , what is the value of dy÷dx at x=e?

Answer 1

if y=tan u , u=v-1÷v, and v=ln x , what is the value of dy÷dx at x=e?

Answer 2

why post it twice???
Assuming you meant u=(v-1)/v, we have
dy'dx = dy/du * du/dv * dv/dx
= (sec^2 u)(1/v^2)(1/x)
at x=e, v=1, u=0, y=0
dy/dx = (1)(1)(1/e) = 1/e