11.5#4

I am struggling with the problem question 4 in 11.5. 

The question regards the partial of w with a point.

So far I have input the variables for x,y,z 

Then I found the partial with respect to s then input the values given in the point. 

The value I calculated was 25.0855369231877 

Please help me out

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Ok, it looks like you did problem 3 correctly, and there were these nice chain rule formula on the bottom of that problem:

∂z/∂s = ∂z/∂x ∂x/∂s + ∂z/∂y ∂y/∂s  and  ∂z/∂t = ∂z/∂x ∂x/∂t + ∂z/∂y ∂y/∂t

You have to do exactly what you did there using those formulas, except now you have three variables so you'd so you'd need to go just a little bit further:

∂w/∂s = ∂w/∂x ∂x/∂s + ∂w/∂y ∂y/∂s + ∂w/∂z ∂z/∂s  

and 

∂w/∂t = ∂w/∂x ∂x/∂t + ∂w/∂y ∂y/∂t + ∂w/∂z ∂z/∂t

I can't tell exactly where you went wrong because YOU DIDN'T SHOW ME YOUR CALCULATIONS, but it *looks* like you actually tried to do that, and only tangled up in the algebra--on that score you would benefit from keeping the calculation of the separate terms in those sums separated and then only combine them once you've got them all done.