- #1
Nylex
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Hi, I' not sure if I've done this question correctly so I just want someone to tell me where I've gone wrong (if I have).
Evaluate the following determinant as a product of two terms. Hence find, in terms of p the values of x for which it vanishes.
Grr, I can't seem to use LaTeX properly so I'll just "draw" the determinant:
x x 0
0 x p
-2x -p x
= x \left\vert \begin{array}{cc} x & p\\-p & x \end{array}\right\vert - x \left\vert \begin{array}{cc} 0 & p\\-2x & x \end{array}\right\vert
= x(x^2 + p^2) - x(2xp)
=x^3 + p^2.x - 2x^2.p
- x(x^2 - 2px + p^2) = 0
x = {-(-2p) +- [(-2p)^2 - 4.1.p^2]^1/2}/2
x = [2p +- (4p^2 - 4p^2)^1/2]/2
x = p
It doesn't look right to me :/.
Evaluate the following determinant as a product of two terms. Hence find, in terms of p the values of x for which it vanishes.
Grr, I can't seem to use LaTeX properly so I'll just "draw" the determinant:
x x 0
0 x p
-2x -p x
= x \left\vert \begin{array}{cc} x & p\\-p & x \end{array}\right\vert - x \left\vert \begin{array}{cc} 0 & p\\-2x & x \end{array}\right\vert
= x(x^2 + p^2) - x(2xp)
=x^3 + p^2.x - 2x^2.p
- x(x^2 - 2px + p^2) = 0
x = {-(-2p) +- [(-2p)^2 - 4.1.p^2]^1/2}/2
x = [2p +- (4p^2 - 4p^2)^1/2]/2
x = p
It doesn't look right to me :/.
Last edited:
. Thanks a lot 
.
