SOLUTION: f(x)=x^2-8x+15 find the vertex, the intercepts, and graph the quadratic function (label vertex & intercepts) Write the standard form of the quadratic function. -I have been

Algebra ->  Graphs -> SOLUTION: f(x)=x^2-8x+15 find the vertex, the intercepts, and graph the quadratic function (label vertex & intercepts) Write the standard form of the quadratic function. -I have been      Log On


   



Question 687862: f(x)=x^2-8x+15
find the vertex, the intercepts, and graph the quadratic function (label vertex & intercepts)
Write the standard form of the quadratic function.
-I have been trying at the problem all last night trying to finish up my homework for this last section. I have looked in my college algebra textbook and everything and I am just not getting anywhere. Please please help!

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
f(x)=x^2-8x+15
find the vertex, the intercepts, and graph the quadratic function (label vertex & intercepts)
Write the standard form of the quadratic function.
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f(x = x^2-8x+15
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Complete the square to find the vertex:
f(x) = x^2 -8x + 16 + 15-16
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f(x) = (x-4)^2 -1
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Vertex: (4,-1)
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Intercepts:
y = x^2-8x+15
Let x = 0, then y = 15
y-int is (0,15)
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Let y = 0
x^2 -8x + 15 = 0
Factor:
(x-5)(x-3) =0
x = 5 or x = 3
x-intercepts are (5,0) and (3,0)
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Graph:
graph%28400%2C400%2C-10%2C15%2C-10%2C40%2Cx%5E2+-8x%2B15%29
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Standard form: y = x^2 - 8x + 15
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Cheers,
Stan H.