[mld88]

I'm in a calculus course and I was wondering how to do implicit differentiation. For example:
x^2 + 2xy -y^2 + x = 2 at the point (1,2)

[newb]

i'm in a calculus course and i was wondering how to do implicit differentiation. for example:
x^2 + 2xy -y^2 + x = 2 at the point (1,2)

Let F(x,y) = x^2 + 2xy - y^2 + x - 2 = 0 and that y is a diff fn defined by F.
Then dF/dx = 2x + 2(y + xy') - 2yy' + 1 = 0
so y' = - (2x + 2y + 1)/(2(x - y))
now replace x with 1 and y with 2 and babing!