Can somebody help plzzzz anyone??? Some one ??
1 answer:
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Answer:
Step-by-step explanation:
I used logic and took the easy way around this as opposed to the long, drawn-out algebraic way. I noticed right off that at x = -3 and x = -1 the y values were the same. In the middle of those two x-values is -2, which is the vertex of the parabola with coordinates (-2, 4). That's the h and k in the formula I'm going to use. Then I picked a point from the table to use as my x and y in the formula I'm going to use. I chose (0, 3) because it's easy. The formula for a quadratic is
and I have everything I need to solve for a. Filling in my h, k, x, and y:
and
and
-1 = 4a so
In work/vertex form the equation for the quadratic is
In standard form it's:
Answer:
Please find attached the required graph of the equation, y = x² - 2·x - 8, created using MS Excel
Step-by-step explanation:
The given function required to be plot is y = x² - 2·x - 8
Therefore, the coordinates of the vertex of the parabola formed by the equation (h, k) is given as follows;
h = -(-2)/(2×1) = 1
k = 1² - 2×1 - 8 = -9
The coordinates of the vertex = (1, -9)
The roots of the equation is given when y = 0, as follows;
At the roots, we have;
x² - 2·x - 8 = 0
By factorizing, we get
x² - 2·x - 8 = (x - 4)·(x + 2) = 0
Therefore. the roots of the equation are;
x = 4, and x = -2
The coordinates of the roots are;
(4, 0), and (-2, 0)
Two other points can be found at when x = 3 and when x = 0 as follows;
When x = 3, we have;
y = 3² - 2×3 - 8 = -5
(3, -5)
When x = 0, we have;
y = 0² - 2×0 - 8 = -8
(0, -8)
The five points are;
(1, -9), (4, 0), (-2, 0), (3, -5), (0, -8)
The graph of the equation created using MS Excel showing the five points is attached.
