Question

∂/∂x √ [(X1)^2+(X2)^2+...+(Xn)^2]
X1= X subscript 1

Answer 1

If I am reading this correctly, take derivative with respect to x of the square root

Answer 2

are x1,x2,..xn dependent variables ?

Answer 3

@perl I think the x's are the independent variables. But, you could be right.
This is what I got: \[(1/2) \times (X_{1}^{2}+X_{2}^{2}+....+X_{n}^{2})^{-1/2}\times[∂/∂x(X_{1}^{2}+X_{2}^{2}+....+X_{n}^{2})]\]