SOLUTION: f(x)=x^2-10x-5 The solutions are 5,-30 I need to graph this but don't know how. Could someone please draw me a picture of how it will look on a graph?

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: f(x)=x^2-10x-5 The solutions are 5,-30 I need to graph this but don't know how. Could someone please draw me a picture of how it will look on a graph?      Log On


   



Question 564420: f(x)=x^2-10x-5
The solutions are 5,-30
I need to graph this but don't know how.
Could someone please draw me a picture of how it will look on a graph?

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
f(x)=x^2-10x-5
The solutions are 5,-30
I need to graph this
---
You can always plot points.
y-intercept = (0,-5)
Find the x-intercepts:
x^2-10x-5 = 0
x = [10 +- sqrt(100 - 4*-5)]/2
---
x = [10 +- sqrt(120)]/2
---
x = [10 +- 2sqrt(30)]/2
--
x = 5+sqrt(30) = 10.47 ; x = 5-sqrt(30) = -0.48
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Plot those three points and draw a parabola thru them
opening upwards (because the coefficient of x^2 is positive).
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Cheers,
Stan H.
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