Which equation represents a parabola that opens upward, has a minimum at x = 3, and has a line of symmetry at x = 3?
A. y = x^2 - 6x + 13
B. y = x^2 - 8x + 19
C. y= x^2 - 3x + 6
D. y= x^2 + 6x + 5

Respuesta :

Answer:

[tex]A.\ y = x^2 - 6x + 13[/tex] is the correct answer.

Step-by-step explanation:

We know that vertex equation of a parabola is given as:

[tex]y = a(x-h)^2+k[/tex]

where [tex](h,k)[/tex] is the vertex of the parabola and

[tex](x,y)[/tex] are the coordinate of points on parabola.

As per the question statement:

The parabola opens upwards that means coefficient of [tex]x^{2}[/tex] is positive.

Let [tex]a = +1[/tex]

Minimum of parabola is at x = 3.

The vertex is at the minimum point of a parabola that opens upwards.

[tex]\therefore[/tex] [tex]h = 3[/tex]

Putting value of a and h in the equation:

[tex]y = 1(x-3)^2+k\\\Rightarrow y = (x-3)^2+k\\\Rightarrow y = x^2-6x+9+k[/tex]

Formula used: [tex](a-b)^2=a^{2} +b^{2} -2\times a \times b[/tex]

Comparing the equation formulated above with the options given we can observe that the equation formulated above is most similar to option A.

Comparing [tex]y = x^2 - 6x + 13[/tex] and [tex]y = x^2-6x+9+k[/tex]

13 = 9+k

k = 4

Please refer to the graph attached.

Hence, correct option is [tex]A.\ y = x^2 - 6x + 13[/tex]

Ver imagen isyllus

Answer:

A. y = x^2 -6x + 13

Step-by-step explanation: