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8x^2+6xy-5sqrt(10)x-3sqrt(10)y-22=0 canonical form

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         2         ____         ____            
-22 + 8*x  - 5*x*\/ 10  - 3*y*\/ 10  + 6*x*y = 0
$$8 x^{2} + 6 x y - 5 \sqrt{10} x - 3 \sqrt{10} y - 22 = 0$$
8*x^2 + 6*x*y - 5*sqrt(10)*x - 3*sqrt(10)*y - 22 = 0
Detail solution
Given line equation of 2-order:
$$8 x^{2} + 6 x y - 5 \sqrt{10} x - 3 \sqrt{10} y - 22 = 0$$
This equation looks like:
$$a_{11} x^{2} + 2 a_{12} x y + 2 a_{13} x + a_{22} y^{2} + 2 a_{23} y + a_{33} = 0$$
where
$$a_{11} = 8$$
$$a_{12} = 3$$
$$a_{13} = - \frac{5 \sqrt{10}}{2}$$
$$a_{22} = 0$$
$$a_{23} = - \frac{3 \sqrt{10}}{2}$$
$$a_{33} = -22$$
To calculate the determinant
$$\Delta = \left|\begin{matrix}a_{11} & a_{12}\\a_{12} & a_{22}\end{matrix}\right|$$
or, substitute
$$\Delta = \left|\begin{matrix}8 & 3\\3 & 0\end{matrix}\right|$$
$$\Delta = -9$$
Because
$$\Delta$$
is not equal to 0, then
find the center of the canonical coordinate system. To do it, solve the system of equations
$$a_{11} x_{0} + a_{12} y_{0} + a_{13} = 0$$
$$a_{12} x_{0} + a_{22} y_{0} + a_{23} = 0$$
substitute coefficients
$$8 x_{0} + 3 y_{0} - \frac{5 \sqrt{10}}{2} = 0$$
$$3 x_{0} - \frac{3 \sqrt{10}}{2} = 0$$
then
$$x_{0} = \frac{\sqrt{10}}{2}$$
$$y_{0} = - \frac{\sqrt{10}}{2}$$
Thus, we have the equation in the coordinate system O'x'y'
$$a'_{33} + a_{11} x'^{2} + 2 a_{12} x' y' + a_{22} y'^{2} = 0$$
where
$$a'_{33} = a_{13} x_{0} + a_{23} y_{0} + a_{33}$$
or
$$a'_{33} = - \frac{5 \sqrt{10} x_{0}}{2} - \frac{3 \sqrt{10} y_{0}}{2} - 22$$
$$a'_{33} = -27$$
then equation turns into
$$8 x'^{2} + 6 x' y' - 27 = 0$$
Rotate the resulting coordinate system by an angle φ
$$x' = \tilde x \cos{\left(\phi \right)} - \tilde y \sin{\left(\phi \right)}$$
$$y' = \tilde x \sin{\left(\phi \right)} + \tilde y \cos{\left(\phi \right)}$$
φ - determined from the formula
$$\cot{\left(2 \phi \right)} = \frac{a_{11} - a_{22}}{2 a_{12}}$$
substitute coefficients
$$\cot{\left(2 \phi \right)} = \frac{4}{3}$$
then
$$\phi = \frac{\operatorname{acot}{\left(\frac{4}{3} \right)}}{2}$$
$$\sin{\left(2 \phi \right)} = \frac{3}{5}$$
$$\cos{\left(2 \phi \right)} = \frac{4}{5}$$
$$\cos{\left(\phi \right)} = \sqrt{\frac{\cos{\left(2 \phi \right)}}{2} + \frac{1}{2}}$$
$$\sin{\left(\phi \right)} = \sqrt{1 - \cos^{2}{\left(\phi \right)}}$$
$$\cos{\left(\phi \right)} = \frac{3 \sqrt{10}}{10}$$
$$\sin{\left(\phi \right)} = \frac{\sqrt{10}}{10}$$
substitute coefficients
$$x' = \frac{3 \sqrt{10} \tilde x}{10} - \frac{\sqrt{10} \tilde y}{10}$$
$$y' = \frac{\sqrt{10} \tilde x}{10} + \frac{3 \sqrt{10} \tilde y}{10}$$
then the equation turns from
$$8 x'^{2} + 6 x' y' - 27 = 0$$
to
$$6 \left(\frac{\sqrt{10} \tilde x}{10} + \frac{3 \sqrt{10} \tilde y}{10}\right) \left(\frac{3 \sqrt{10} \tilde x}{10} - \frac{\sqrt{10} \tilde y}{10}\right) + 8 \left(\frac{3 \sqrt{10} \tilde x}{10} - \frac{\sqrt{10} \tilde y}{10}\right)^{2} - 27 = 0$$
simplify
$$9 \tilde x^{2} - \tilde y^{2} - 27 = 0$$
$$- 9 \tilde x^{2} + \tilde y^{2} + 27 = 0$$
Given equation is hyperbole
$$\frac{\tilde x^{2}}{3} - \frac{\tilde y^{2}}{27} = 1$$
- reduced to canonical form
The center of canonical coordinate system at point O
   ____     ____  
 \/ 10   -\/ 10   
(------, --------)
   2        2     

Basis of the canonical coordinate system
$$\vec e_1 = \left( \frac{3 \sqrt{10}}{10}, \ \frac{\sqrt{10}}{10}\right)$$
$$\vec e_2 = \left( - \frac{\sqrt{10}}{10}, \ \frac{3 \sqrt{10}}{10}\right)$$
Invariants method
Given line equation of 2-order:
$$8 x^{2} + 6 x y - 5 \sqrt{10} x - 3 \sqrt{10} y - 22 = 0$$
This equation looks like:
$$a_{11} x^{2} + 2 a_{12} x y + 2 a_{13} x + a_{22} y^{2} + 2 a_{23} y + a_{33} = 0$$
where
$$a_{11} = 8$$
$$a_{12} = 3$$
$$a_{13} = - \frac{5 \sqrt{10}}{2}$$
$$a_{22} = 0$$
$$a_{23} = - \frac{3 \sqrt{10}}{2}$$
$$a_{33} = -22$$
The invariants of the equation when converting coordinates are determinants:
$$I_{1} = a_{11} + a_{22}$$
     |a11  a12|
I2 = |        |
     |a12  a22|

$$I_{3} = \left|\begin{matrix}a_{11} & a_{12} & a_{13}\\a_{12} & a_{22} & a_{23}\\a_{13} & a_{23} & a_{33}\end{matrix}\right|$$
$$I{\left(\lambda \right)} = \left|\begin{matrix}a_{11} - \lambda & a_{12}\\a_{12} & a_{22} - \lambda\end{matrix}\right|$$
     |a11  a13|   |a22  a23|
K2 = |        | + |        |
     |a13  a33|   |a23  a33|

substitute coefficients
$$I_{1} = 8$$
     |8  3|
I2 = |    |
     |3  0|

$$I_{3} = \left|\begin{matrix}8 & 3 & - \frac{5 \sqrt{10}}{2}\\3 & 0 & - \frac{3 \sqrt{10}}{2}\\- \frac{5 \sqrt{10}}{2} & - \frac{3 \sqrt{10}}{2} & -22\end{matrix}\right|$$
$$I{\left(\lambda \right)} = \left|\begin{matrix}8 - \lambda & 3\\3 & - \lambda\end{matrix}\right|$$
     |                ____|   |                ____|
     |           -5*\/ 10 |   |           -3*\/ 10 |
     |    8      ---------|   |    0      ---------|
     |               2    |   |               2    |
K2 = |                    | + |                    |
     |     ____           |   |     ____           |
     |-5*\/ 10            |   |-3*\/ 10            |
     |---------     -22   |   |---------     -22   |
     |    2               |   |    2               |

$$I_{1} = 8$$
$$I_{2} = -9$$
$$I_{3} = 243$$
$$I{\left(\lambda \right)} = \lambda^{2} - 8 \lambda - 9$$
$$K_{2} = -261$$
Because
$$I_{2} < 0 \wedge I_{3} \neq 0$$
then by line type:
this equation is of type : hyperbola
Make the characteristic equation for the line:
$$- I_{1} \lambda + I_{2} + \lambda^{2} = 0$$
or
$$\lambda^{2} - 8 \lambda - 9 = 0$$
$$\lambda_{1} = 9$$
$$\lambda_{2} = -1$$
then the canonical form of the equation will be
$$\tilde x^{2} \lambda_{1} + \tilde y^{2} \lambda_{2} + \frac{I_{3}}{I_{2}} = 0$$
or
$$9 \tilde x^{2} - \tilde y^{2} - 27 = 0$$
$$\frac{\tilde x^{2}}{3} - \frac{\tilde y^{2}}{27} = 1$$
- reduced to canonical form