31,512 views
6 votes
6 votes
I need help with my homework. I have the answer but I need to know if my answer is correct please help thank you in advance

I need help with my homework. I have the answer but I need to know if my answer is-example-1
User Abinash
by
3.0k points

1 Answer

17 votes
17 votes

Step-by-step explanation

Since we have the parabola:


f(x)=6x^2-54

We first need to obtain the roots in order to compute the x-intercepts:


\mathrm{Add\: }54\mathrm{\: to\: both\: sides}
6x^2-54+54=0+54

Simplify:


6x^2=54
\mathrm{Divide\: both\: sides\: by\: }6
(6x^2)/(6)=(54)/(6)

Simplify:


x^2=9

For x^2 = f(a) the solutions are x= √f(a) :


x=√(9),\: x=-√(9)

Computing the square root we get:


\mathrm{X\: Intercepts}\colon\: \mleft(3,\: 0\mright),\: \mleft(-3,\: 0\mright)

b) Computing the vertex:


\mathrm{The\: vertex\: of\: an\: up-down\: facing\: parabola\: of\: the\: form}\: y=ax^2+bx+c\: \mathrm{is}\: x_v=-(b)/(2a)
\mathrm{The\: parabola\: params\: are\colon}
a=6,\: b=0,\: c=-54
x_v=-(b)/(2a)
x_v=-(0)/(2\cdot\:6)
\mathrm{Simplify}\colon
x_v=0

Plugging in x_v to find the y_v value:


y_v=6\cdot\: 0^2-54

Simplify:


y_v=-54
\mathrm{Therefore\: the\: parabola\: vertex\: is}\colon
\mleft(0,\: -54\mright)

User Artur Bodera
by
2.9k points