Representa una funcion cuadratica con las siguientes caracteristicas a: vertice en (2,-4)y b: puntos de corte con el eje x(-2,0)y (g,0)
Question
Answer:
The quadratic function is given by the equationy=0.25(x-2)²-4, and the value of g is 6.
We first write this in vertex form, using the information we have:
y=a(x-h)²+k, where (h, k) is the vertex
y=a(x-2)²-4
We now substitute one of the points the function goes through into our x and y variables to solve for a:
0=a(-2-2)²-4
0=a(-4)²-4
0=16a-4
Add 4 to both sides:
0+4 = 16a-4+4
4=16a
Divide both sides by 16:
4/16 = 16a/16
0.25 = a
This gives us the function
y=0.25(x-2)²-4
Now we write this in standard form:
y=0.25(x-2)(x-2)-4
y=0.25(x*x-2*x-2*x-2(-2))-4
y=0.25(x²-2x-2x+4)-4
y=0.25(x²-4x+4)-4
y=0.25x²-1x+1-4
y=0.25x²-1x-3
Using the quadratic formula,
[tex]x=\frac{-(-1)\pm\sqrt{(-1)^2-4(0.25)(-3)}}{2(0.25)} \\ \\=\frac{1\pm \sqrt{1--3}}{0.5}=\frac{-1\pm \sqrt{4}}{0.5} \\ \\=\frac{1\pm2}{0.5}=\frac{1+2}{0.5}\text{ or }\frac{1-2}{0.5} \\ \\=\frac{3}{0.5}\text{ or }\frac{-1}{0.5}=6\text{ or }-2[/tex]
We already had the root (-2, 0); this gives us the value of g, 6.
solved
general
10 months ago
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