Complex Numbers Help (1 Viewer)

[Web Addict]

Help Please.
If p is real and p is in between -2 and 2, show that the roots of the equation, x^2+px+1=0 are non-real complex numbers with modulus, 1.
I have shown that the roots are non-real complex numbers, but how do I show that the modulus is 1?
Thank you.

 

[oh well]

Help Please.
If p is real and -2<p<2, show that the roots of the equation, x^2+px+1=0 are non-real complex numbers with modulus, 1.
I have shown that the roots are non-real complex numbers, but how do I show that the modulus is 1?
Thank you.

I don't get the question :S WHat is the 'actual' question?

 

[Web Addict]

Sorry. I just edited the post above.

 

[rolpsy]

Let the root be α. Since the coefficients are real, roots are in conjugate pairs. Hence the other root is α* (conjugate).

Using the product of roots

 

[oh well]

Let the root be α. Since the coefficients are real, roots are in conjugate pairs. Hence the other root is α* (conjugate).

Using the product of roots

+1

 

[Web Addict]

Thank you so much.