Pls help
2 answers:
Answer:
B
Step-by-step explanation:
Given
x² + 2x + 8 ( to find the solutions equate to zero )
x² + 2x + 8 = 0 ( subtract 8 from both sides )
x² + 2x = - 8
To solve we can use the method of completing the square
add ( half the coefficient of the x- term )² to both sides
x² + 2(1)x + 1 = - 8 + 1
(x + 1)² = - 7 ( take the square root of both sides )
x + 1 = ± = ± i
Subtract 1 from both sides )
x = - 1 ± i
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Given:
The image of a lens crosses the x-axis at –2 and 3.
The point (–1, 2) is also on the parabola.
To find:
The equation that can be used to model the image of the lens.
Solution:
If the graph of polynomial intersect the x-axis at c, then (x-c) is a factor of the polynomial.
It is given that the image of a lens crosses the x-axis at –2 and 3. It means (x+2) and (x-3) are factors of the function.
So, the equation of the parabola is:
...(i)
Where, k is a constant.
It is given that the point (–1, 2) is also on the parabola. It means the equation of the parabola must be satisfy by the point (-1,2).
Putting in (i), we get
Divide both sides by -4.
Putting in (i), we get
Therefore, the required equation of the parabola is .
Note: All options are incorrect.