⇒x0=−513,y0=512,z0=6on solving the system of equations.
Thus, the center of the conicoid is P(−513,512,6).
2] A conicoid is called a central conicoid if it has a unique center.
To check if the given conicoid has a unique center, we need to show that the system of linear equations;
4x0+y0+z0=−2x0+4y0−z0=1x0−y0+0z0=−5
⇒⎝⎛41114−11−10⎠⎞⎝⎛x0y0z0⎠⎞=⎝⎛−21−5⎠⎞ , in matrix form has a unique solution (exactly one solution) by showing that the determinant of the coefficient matrix is not equal to zero. That is we need to show that
∣∣41114−11−10∣∣=0
Now,
∣∣41114−11−10∣∣=−10=0
Thus the coefficient matrix is invertible and x0,y0,z0 are unique from the properties of matrix, with
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