Find the zeros of the function: x2 - 2x + 8
T typ New member Joined May 24, 2017 Messages 1 May 24, 2017 #1 Find the zeros of the function: x2 - 2x + 8 Last edited by a moderator: May 26, 2017
D Deleted member 4993 Guest May 24, 2017 #2 typ said: x2 - 2x + 8 Click to expand... What method have you been taught - factorization? - completing square? - quadratic formula?
typ said: x2 - 2x + 8 Click to expand... What method have you been taught - factorization? - completing square? - quadratic formula?
H HallsofIvy Elite Member Joined Jan 27, 2012 Messages 7,763 May 25, 2017 #3 typ said: x2 - 2x + 8 Click to expand... x2- 2x+ 8= x2- 2x+ 1+ 7= (x- 1)2+ 7 Setting that equal to 0, (x- 1)2= -7 so x must be a complex number. If the problem is to find the zeros of x2- 2x- 8 then x2- 2x+ 1- 9= (x- 1)2- 9. Setting that equal to 0, (x- 1)2= 9 which should be easy to solve.
typ said: x2 - 2x + 8 Click to expand... x2- 2x+ 8= x2- 2x+ 1+ 7= (x- 1)2+ 7 Setting that equal to 0, (x- 1)2= -7 so x must be a complex number. If the problem is to find the zeros of x2- 2x- 8 then x2- 2x+ 1- 9= (x- 1)2- 9. Setting that equal to 0, (x- 1)2= 9 which should be easy to solve.
