Question

Use implicit differentiation to find an equation of the tangent line to the curve x^2+xy+y^2=3 at the point (1,1)

Answer 1

=2x+xy'+y+2yy'=0
=y'(x+2y)=2x+y

y'=(2x+y)/(x+2y)
plugging in (1,1) i get y'=1
plugging 1 into point-slope form i get y=x
help?

Answer 2

2x+xy'+y+2yy'=0
gives
y' (x+2y) = -2x-y
isn't it ?

Answer 3

It sure does! Time for my coffee I guess, thanks :)

Answer 4

watch your signs!

Answer 5

need any further assistance with this??

Answer 6

No, i've got this thanks!