Best Answer: <span> y=18x^2+9x+14
y=18(x^2+(1/2)x + 1/16) + 14 - 9/8
y = 18(x + 1/4)^2 + 103/8
For y = a*(x - h)^2 + k, (h, k) the vertex
Your vertex: (- 1/4, 103/8)
Equation of axis of symmetry is x = (x-coordinate of vertex) OR x = - 1/4
y-intercept is y-value when x = 0, y = 14
x-intercept(s) do not exist for this upward opening parabola whose vertex y-value is above the x-axis.
The minimum of the function is the y-value of the vertex, 103/8.
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Seems like Dizzle was in too much of a hurry and Jeff just copied Dizzle's answer.
The correct way of doing what dizzle TRIED to do:
For y = a*x^2 + b*x + c, the vertex occurs when x = - b / (2*a)
y=18x^2+9x+14
a = 18
b = 9
- b / (2*a) = - (9) / (2*18) = - 9 / 36 = - 1/4
Take that value for x, evaluate function at that value to get y.
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Was so giddy about dizzle's faux pas that I originally did this work. May as well share it:
x-intercept(s) can be found by setting function equal to zero and solving:
y = 18(x + 1/4)^2 + 103/8
0 = 18(x + 1/4)^2 + 103/8
18(x + 1/4)^2 = - 103/8
(x + 1/4)^2 = - 103/144
x + 1/4 = +/- i*sqrt(103)/12
x = - 1/4 +/- i*sqrt(103)/12 OR x = [- 3 +/- i*sqrt(103)] / 12
These are the roots of the equation f(x) = 0
Since the roots are complex, there are no x-intercepts. The function is entirely above the x-axis. </span>
300,000 + 25,000 + 800 + 9
Distribute the 2 to all terms within the parenthesis
2(x + 8) = 2x + 16
2x + 16 = x + 20
Isolate the x. Subtract x from both sides and 16
2x (-x) + 16 (-16) = x (-x) + 20 (-16)
2x - x = 20 - 16
Simplify. Combine like terms.
x = 4
C. 4 is your answer
hope this helps
