Question

Calculus 3 - Differentials

http://i.imgur.com/XwSsYlQ.png

Why isn't 25, 40, and 50 squared? According to (R1)^2, (R2)^2, and (R3)^2 they're squared

Answer 1

Maybe it's just a typo

Answer 2

I checked the book and used Google and it's correct

Answer 3

the R^2s or the fact that they're not squared in the denominator?

Answer 4

The fact that they're not squared Every website that provides a solution seems to have skipped the R^2s and got R1, R2, and R2 without being squared

Answer 5

They have it as 1/R1 + 1/R2 + 1/R3 but the way I did it (along with that picture given done by a professor and other students) I got 1/R1^2 + 1/R2^2 + 1/R3^2

Answer 6

im somewhat confused..
@Mertsj @satellite73 @amistre64 @TuringTest @Zarkon

Answer 7

Here is another solution from a different professor: https://www.sccollege.edu/Faculty/RScott/Documents/11-4_Prob_31.pdf same method but the answer came out differently when I calculated

Answer 8

I got about ~0.0018 which =/= 1/17

Answer 9

well he did square them didn't he

Answer 10

Seems like he did but my answer came out as ~0.0018 which =/= 1/17, but if I were to NOT square it I would have gotten 1/17

Answer 11

Here's the computation when the Rs are squared: https://tinyurl.com/qjvasvv

Answer 12

and here's the computation when the Rs are NOT squared: https://tinyurl.com/ph9y4l3

Answer 13

because dRi=0.005*Ri so (R^2/R1^2)*(0.005*R1)=(R^2/R1) *0.005
same for other dRi