SOLUTION: Solve x2 - 2x - 8 = 0 by graphing. The x intercepts are ? and ?.

Algebra ->  Algebra  -> Coordinate-system -> SOLUTION: Solve x2 - 2x - 8 = 0 by graphing. The x intercepts are ? and ?.      Log On

Ad: Algebra Solved!™: algebra software solves algebra homework problems with step-by-step help!
Ad: Algebrator™ solves your algebra problems and provides step-by-step explanations!

   

Question 240697: Solve x2 - 2x - 8 = 0 by graphing. The x intercepts are ? and ?.
Answer by rapaljer(4551) About Me  (Show Source):
You can put this solution on YOUR website!
Graph y=x^2 -2x-8 with a calculator.
graph%28300%2C300%2C-6%2C6%2C-6%2C+12%2Cx%5E2-2x-8%29+

As you can see, the x-intercepts are at x=-2 and x=4.

This can also be determined algebraically by letting y=0 and solving
0=x^2-2x-8
0=(x-4)(x+2)
x=4 or x=-2

Dr. Robert J. Rapalje, Retired
Seminole State College of Florida
Altamonte Springs Campus