Question

find the first derivative of cos(xy) = 2y

Answer 1

-sin(xy)(xy'+y) all over 2 = y'

Answer 2

oops

Answer 3

expand, collect your y's, and factor again

Answer 4

-sinxy = 2y'/xy'+y

Answer 5

cos(xy) = 2y

-sin(xy) (xy)' = 2 y'

-sin(xy) (y+xy') = 2 y'

-y sin(xy) -x sin(xy) y' = 2 y'

-y sin(xy) = 2 y' + x sin(xy) y'

-y sin(xy) = y' 2(+ x sin(xy))

etc

Answer 6

assuming of course this is "wrt.x"

Answer 7

ohh.. i now see my mistake

Answer 8

might want to move that 2 back inside the (....) its trying to escape

Answer 9

y' = -ysinxy / 2+xsinxy?