Question

xy=4 and dy/dt=-6, find dx/dt when x=4

Answer 1

\[xy=4\\y=\frac{4}{x}\]

Answer 2

\[y'=-\frac{4}{x^2}x'\]

Answer 3

plug in the numbers, solve for \(x'\)

Answer 4

I keep getting 24 but my teacher put 6 on the answer key. Am I crazy?

Answer 5

\[-6=-\frac{4}{4^2}x'\]

Answer 6

yeah i get 24 too

Answer 7

cool

Answer 8

thanks.

Answer 9

yw