The vertex form of the equation of a parabola is [tex]y = (x - 4)^2 + 22[/tex]. What is the standard form of the equation?

A. [tex]y = x^2 + x + 11[/tex]

B. [tex]y = 4x^2 - 8x + 38[/tex]

C. [tex]y = x^2 - 8x + 38[/tex]

D. [tex]y = x^2 + 8x + 22[/tex]



Answer :

To convert the vertex form of the equation of a parabola to its standard form, we need to expand the given expression. The vertex form of the equation provided is [tex]\( y = (x-4)^2 + 22 \)[/tex].

Step-by-step, we proceed as follows:

1. Expand the square:
[tex]\[ (x - 4)^2 \][/tex]
By applying the formula [tex]\((a - b)^2 = a^2 - 2ab + b^2\)[/tex]:
[tex]\[ (x - 4)^2 = x^2 - 2 \cdot 4 \cdot x + 4^2 = x^2 - 8x + 16 \][/tex]

2. Add the constant term:
[tex]\[ y = x^2 - 8x + 16 + 22 \][/tex]

3. Combine like terms:
[tex]\[ y = x^2 - 8x + (16 + 22) = x^2 - 8x + 38 \][/tex]

Thus, the standard form of the equation is:
[tex]\[ y = x^2 - 8x + 38 \][/tex]

Comparing this with the choices provided:
- A. [tex]\( y = x^2 + x + 11 \)[/tex]
- B. [tex]\( y = 4x^2 - 8x + 38 \)[/tex]
- C. [tex]\( y = x^2 - 8x + 38 \)[/tex]
- D. [tex]\( y = x^2 + 8x + 22 \)[/tex]

The correct answer is:
[tex]\[ \boxed{C} \][/tex]