Question

Partial derivative of f(x,y): x*y^-1 + y*z^-1 +z*x^-1 wrt x? Wouldn't it just be 1/y + z/x^2 ?

Answer 1

close, your last term is missing a negative.

Answer 2

Why would the last term be negative?

Answer 3

what's the derivative of lets say 2\x?

Answer 4

with respect to x of course.

Answer 5

2/x^2 ?

Answer 6

no, it's - 2/x^2

Answer 7

because the exponent of x is really -1 before the derivative right?

Answer 8

Oh okay. I get it.

Answer 9

so basically 2*x^-1 --> 2*-1x^(-2)

Answer 10

so -2/x^2

Answer 11

yes exactly!

Answer 12

My calculus is a little rusty lol.

Answer 13

tell me about it, I haven't done math in over 5 years lol.

Answer 14

Oh wow, you don't seem to rusty though :) So partial derivative wrt x would just be 1/y + -z/x^2 ?

Answer 15

too*

Answer 16

yes! But trust me it is, I went as high as linear algebra and I will not be able to help you do anything with matrices...or anything too complex.

Answer 17

Yeah, I took linear algebra and the math was easy but conceptually it was difficult. Thanks for the help though! :)

Answer 18

no problem.