Given line equation of 2-order: 5x2+3y2=0 This equation looks like: a11x2+2a12xy+2a13x+a22y2+2a23y+a33=0 where a11=5 a12=0 a13=0 a22=3 a23=0 a33=0 To calculate the determinant Δ=a11a12a12a22 or, substitute Δ=5003 Δ=15 Because Δ is not equal to 0, then find the center of the canonical coordinate system. To do it, solve the system of equations a11x0+a12y0+a13=0 a12x0+a22y0+a23=0 substitute coefficients 5x0=0 3y0=0 then x0=0 y0=0 Thus, we have the equation in the coordinate system O'x'y' a33′+a11x′2+2a12x′y′+a22y′2=0 where a33′=a13x0+a23y0+a33 or a33′=0 a33′=0 then equation turns into 5x′2+3y′2=0 Given equation is degenerate ellipse (55)2x~2+(33)2y~2=0 - reduced to canonical form The center of canonical coordinate system at point O
(0, 0)
Basis of the canonical coordinate system e1=(1,0) e2=(0,1)
Invariants method
Given line equation of 2-order: 5x2+3y2=0 This equation looks like: a11x2+2a12xy+2a13x+a22y2+2a23y+a33=0 where a11=5 a12=0 a13=0 a22=3 a23=0 a33=0 The invariants of the equation when converting coordinates are determinants: I1=a11+a22
I1=8 I2=15 I3=0 I(λ)=λ2−8λ+15 K2=0 Because I3=0∧I2>0 then by line type: this equation is of type : degenerate ellipse Make the characteristic equation for the line: −I1λ+I2+λ2=0 or λ2−8λ+15=0 λ1=5 λ2=3 then the canonical form of the equation will be x~2λ1+y~2λ2+I2I3=0 or 5x~2+3y~2=0 (55)2x~2+(33)2y~2=0 - reduced to canonical form