Show that x^2 + 6x + 5 can be written in the form (x+3)^2 + a where a is an constant to be determined.

Thanks mates.

Question

Show that x^2 + 6x + 5 can be written in the form (x+3)^2 + a where a is an constant to be determined. 


Thanks mates.

anonymous · Answer

What happened here was the opposite of FOIL. They've taken x^2+6x+5 and turned it into it's un-factored form: (x+3)^2. If you FOIL that out, you get x^2+6x+9. Since you need the number nine to be a 5, it is safe to assume that a=-4.

anonymous · Answer

OOOh! Well done my dear friend! Very nice explaining indeed!

anonymous · Answer

Sure :)

anonymous · Answer

This is a handy way to complete the square without actually completing the square.

anonymous · Answer

Sure is

anonymous · Answer

Helps with general quadratics and conic sections too.  ;-)

anonymous · Answer

Ive got another one now. 
Sketch the graph of y=x^2+6x+5 giving the equation of the axis of symmetry and the co-ordinates of the vertex.

anonymous · Answer

@cshalvey

anonymous · Answer

@Anlexia help me

anonymous · Answer

@satellite73 @TuringTest @estudier  does anyone know how to do this bit?

anonymous · Answer

Just put it up as another question, you will get help....