find the x intercept of f(x)=x2-9x+7

Question

What are the x-intercepts of f(x)=x2−9x+7

Answer 1

1. At the x intercepts, y=0, so set this equal to 0

• x²-9x+7=0

2. To solve equations like this, factor if possible.  (If not, consider completing the square, or the quadratic formula)

• This does NOT factor, so I'll use the quadratic formula (hopefully you know this, x=-b plus/minus....)
• x =[ 9+/- sqrt (81-28)]/2
• x=[ 9+/- sqrt (53)]/2

 

The answers aren't pretty, but those are your values.  If you need to graph those, use a calculator to get approximately  0.86 and 8.14