Homework Statement
Suppose a,c>0 and b^2-4ac>0 . Explain how you could find x_1, x_2 ε ℝ
such that a(x_1) ^2+bx_1x_2+c(x_2)^2<0 .
Homework Equations
q\begin{pmatrix}x_1\\x_2\end{pmatrix} = a(x_1)^2+bx_1x_2+c(x_2)^2
The Attempt at a Solution
I'm not sure where to go with this...
The other eigenvalue is the same isn't it? So there's only one distinct eigenvalue? For the matrix B^3, I put the eigenvalues on the diagonal and then 0's in the other two spots.
Ok, thanks for the help everyone. Does this mean then that B^3 has eigenvalues that are equal to -3√3? I just cubed the eigenvalues for B after factoring out a √3.
Homework Statement
Suppose B is a real 2x2 matrix with the following eigenvalue:
\frac{√3}{2} + \frac{3i}{2}.
Find B^3.
Homework Equations
One of the hints is to consider diagonalization over C together with the fact
that (\frac{1}{2} + \frac{√3}{2}i)^3 = -1.
The Attempt...