I'm having some trouble understanding the conclusions drawn in the second of these two slides.

Knipsel8.PNG

© Rijksuniversiteit Groningen

Knipsel9.PNG

© Rijksuniversiteit Groningen

I can see that both X_{1} and X _{2} cannot be 0 given the equations.

However, I don't understand how they came to X_{1} ^{2} = X _{2} ^{2}

Also I do see that the four critical points hold, but again I don't know how they came to these points.

Is that simply something you should be able to see or is it also possible to determine them by computation.

Is there someone who can help me with this?

Knipsel8.PNG

© Rijksuniversiteit Groningen

Knipsel9.PNG

© Rijksuniversiteit Groningen

I can see that both X

However, I don't understand how they came to X

Also I do see that the four critical points hold, but again I don't know how they came to these points.

Is that simply something you should be able to see or is it also possible to determine them by computation.

Is there someone who can help me with this?

reinout-g Mar 17, 2014