Question

find the tangents of the curve xy=18 from (4,4) please help. the answers are x+ 2y = 12 and 2x + y = 12

Answer 1

what is the dy/dx of the equation

Answer 2

make y the subject then differentiate

Answer 3

so dy/dx = x??

Answer 4

nope

\[y = \frac{18}{x}\]which in index form is

\[y = 18x^{-1}\]

now you can find the derivative

Answer 5

dy/dx = 18? aaah not sure..

Answer 6

nope

\[y' = - \frac{18}{x^2}\]

Answer 7

the point (4, 4) isn't on the curve...

Answer 8

okay okay thanks!!!!