Respuesta :
Answer:
Listed below
Step-by-step explanation:
This is a cuadratic function excercise.
We know that cuadratic functions have the following formula:
[tex]y=ax^{2} +bx+c[/tex]
The graphic of this function will give us a parabola, that can be graphed knowing four points: the two or less x-intercepts, the y-intercept, and the vertex (Xv;Yv).
A) The vertex
The vertex is a point on the graph, so we have to know it's value on the X axis and on the Y axis.
To know the value of Xv we can calculate it using the following formula:
[tex]Xv=\frac{-b}{2a}[/tex]
We know that in this case:
[tex]a=1\\b=-5\\c=-6[/tex]
So we supplant said values on the formula and we get:
[tex]Xv=\frac{-(-5)}{2.1} =\frac{5}{2}=2.5[/tex]
To know the value of Yv, we suppland the value of Xv on the function's formula.
[tex]f(x=\frac{-5}{2})=(\frac{-5}{2}) ^{2} -5.\frac{-5}{2}-6=\frac{51}{4}=12.75[/tex]
So we know now that
[tex]Xv=\frac{-5}{2}[/tex] and [tex]Yv=\frac{51}{4}[/tex]
b) The y-intercept is the value of C on the function's formula. We know that c=-6, so
[tex]Y=-6[/tex]
c) The x-intercepts can be resolved using the following formula:
[tex]x=\frac{-b+-\sqrt[2]{b^{2}-4ac} }{2a} \\\\x=\frac{-5+-\sqrt[2]{(-5)^{2}-4.1.(-6)} }{2.1} \\x=\frac{-(-5)+-\sqrt[2]{25+24} }{2}\\x=\frac{5+-\sqrt[2]{49} }{2.1}\\x=\frac{5+-7 }{2.1}[/tex]
This means that this formula can have two posisible solutions:
[tex]x= \frac{5+7}{2} =\frac{12}{2}=6[/tex]
Or:
[tex]x= \frac{5+7}{2} =\frac{-2}{2}=-1[/tex]
So that are the X-intercepts: x=6 and x=-1