Computing the second fundamental form - can you spot the error?

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The discussion focuses on computing the second fundamental form for a surface, specifically identifying an error in part g of the calculations. The expected coefficients for IIuu, IIuv, and IIvv are 2, 0, and -2, but the participants have only successfully computed IIz. They are confident that their work leading up to the da component is correct, indicating the issue arises in the final steps. There is a suggestion that the II values for x and y should match those for z, implying a potential oversight. The thread seeks assistance in pinpointing the error in the computations.
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Homework Statement
Compute the second fundamental form of the surface.
Relevant Equations
Standard differential geometry formulas for the second fundamental form with Christoffel symbols.
Hi all. We are computing the second fundamental form corresponding to a surface.

The correct answer should give the coefficients 2, 0, and -2 for IIuu, IIuv, IIvv

We have only been able to compute IIz, and not IIx, IIy where we have functions instead of 2, 0 and -2.

We are 99% certain that everything up to the da component in part (e.) is correct. It is just in the last computations where an apparent errors are. Can you see where the error is in part g?
Screen Shot 2020-12-20 at 8.06.39 PM.png


Screen Shot 2020-12-20 at 8.06.44 PM.png

Screen Shot 2020-12-20 at 8.06.51 PM.png

Screen Shot 2020-12-20 at 8.06.55 PM.png


Screen Shot 2020-12-20 at 8.06.59 PM.png

Screen Shot 2020-12-20 at 8.07.03 PM.png


In part g, the II's corresponding to x and y should be the same as z. It seems like something is missing, perhaps. The second fundamental form were calculated using the following formula.
Screen Shot 2020-12-20 at 8.22.34 PM.png


Thank you!
 
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I am replying to this thread so it no longer shows up on the "unanswered threads" list
 
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