# Finding the points

• November 24th 2008, 11:57 AM
Pommac
Finding the points
Please, help me with this. I have no idea how to solve it

In what points are the tangent to the ellipse parallel to the line y = x?
• November 24th 2008, 04:30 PM
skeeter
Quote:

Originally Posted by Pommac
Please, help me with this. I have no idea how to solve it

In what points are the tangent to the ellipse parallel to the line y = x?

why are the coefficients written that way?

why not just $13x^2 - 12xy + 13y^2 = 2$ ?

in any case, find $\frac{dy}{dx}$ implicitly and set it equal to 1.

solve for x in terms of y or y in terms of x (whichever is easier), and sub the result back into the original equation to solve for the that chosen variable.