For the equation given below, evaluate at the point .

y' at (2,1) = ?

so i tried taking the natural log of everything then differentiating both sides and solving for y'.

ln2 + lne^xy - ln2 + lnx = lny +ln9.78

xy + lnx = lny + ln9.78

(1/y)y' = y + xy' + 1/x + 0

y' = y^2 + xy'y + y/x

y' = y^2+(y/x) / 1-xy

then if you plug in (2,1) i get -1.5 and thats not right =(

any advice?