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Homework Statement
whether (Aijxi)/xk is a tenzor or not, if it is, what kind? (co-variant or contra-variant).
Homework Equations
given that Aij is a second degree tenzor and x are the coordinates.
The Attempt at a Solution
Aijxi)/ is clearly a first degree contra-variant tenzor, therefore the question reduces to whether
Bj/xk
is a tenzor.
so I do the transformations, and get a normal tenzor transformation on the numerator (from B), and a normal transformation on the denominator (from x), so if we are working in 1 dimention, it's simply 1/(dx/dx')*x = (dx'/dx)*1/x, which means a co-variant tenzor in the denominator transforms as a contra-variant tenzor.
however, if the dimention is greater than 1, I get a sum of lots of partial derivetives, and 1 devided by that equals who knows what... so in that case I fail to determine whether it is a tenzor or not, it doesn't really look like one to me, but I'm really not sure, maybe there's some algebric work to do and make it look like a tenzor again?
Homework Statement
what kind of a tenzor (co-variant or contra-variant) is:
d2(phi)/dxpdxq
Homework Equations
phi is a scalar function
x are the coordinates
The Attempt at a Solution
the questions states that it is a tenzor, and asks what kind of a tenzor it is, yet I don't understand how come it is a tenzor.
the expression is
d2(phi)/dxpdxq =
d/dxp(d(phi)/dxq), and d(phi)/dxq is a co-variant tenzor, so I do the transformation for it, and the take the derivative by xp, I get 2 expresion, which one looks like a tenzor transformation, yet the other a second derivative of x by some x'i, x'j (x' being the new coordinates).
so I don't understand why is that expression a tenzor
thanks
ibc