# Two questions about rotation of this line

1. Aug 28, 2011

### flyingpig

Two questions about rotation of this "line"

1. The problem statement, all variables and given/known data

$$3x^2 - 2\sqrt{3}xy +y^2 = 1$$

2. Relevant equations

$$x = x'\cos\alpha - y'\sin\alpha$$
$$y = x'\sin\alpha + y'\cos\alpha$$

3. The attempt at a solution

The discriminant test is

$$4(3) - 4(3)(1) = 0$$

Supposed to be a parabola, instead we get lines.

One other thing

Supposed that in

$$cot2\alpha = \frac{A - C}{B}$$

And then we get that $$\alpha < 0$$, can that happen? Can we rotate clockwise?

2. Aug 28, 2011

### SteamKing

Staff Emeritus
Re: Two questions about rotation of this "line"

The OP is missing a problem statement. What is it that you are having problems with?