Which function in vertex form is equivalent to f(x) = x2 + x +1? f(x) = (x + one-quarter) squared + three-quarters f(x) = (x + one-quarter) squared + five-quarters f(x) = (x + one-half) squared + three-quarters f(x) = (x + one-half) squared + five-quarters

Respuesta :

The function in vertex form is [tex]f(x)=(x+\frac{1}{2})^{2}+\frac{3}{4}[/tex] ⇒ 3rd answer

Step-by-step explanation:

The vertex form of the quadratic function f(x) = ax² + bx + c is

f(x) = a(x - h)² + k, where

  • a is the coefficient of x²
  • (h , k) are the coordinates of the vertex point
  • [tex]h=\frac{-b}{2a}[/tex] , wher b is the coefficient of x
  • k = f(h), that means value f(x) when x = h

∵ f(x) = x² + x + 1

∴ a = 1 , b = 1

∵ [tex]h=\frac{-b}{2a}[/tex]

- Substitute the values of a and b to find h

∴ [tex]h=\frac{-1}{2(1)}[/tex]

∴ [tex]h=\frac{-1}{2}[/tex]

Substitute the value of x in f(x) by the value of h to find k

∵ f( [tex]\frac{-1}{2}[/tex] ) = [tex](\frac{-1}{2})^{2}+\frac{-1}{2}+1[/tex]

∴ f( [tex]\frac{-1}{2}[/tex] ) = [tex]\frac{1}{4}-\frac{1}{2}+1[/tex]

∴ f( [tex]\frac{-1}{2}[/tex] ) = [tex]\frac{3}{4}[/tex]

- k is the value of f(x) when x = h

∵ h = [tex]\frac{-1}{2}[/tex]

∴ k = f( [tex]\frac{-1}{2}[/tex] )

∴ k = [tex]\frac{3}{4}[/tex]

Substitute the values of a, h and k in the vertex form

∵ f(x) = a(x - h)² + k

∵ a = 1 , [tex]h=\frac{-1}{2}[/tex] , [tex]k=\frac{3}{4}[/tex]

∴ [tex]f(x)=1(x-\frac{-1}{2})^{2}+\frac{3}{4}[/tex]

∴ [tex]f(x)=(x+\frac{1}{2})^{2}+\frac{3}{4}[/tex]

The function in vertex form is [tex]f(x)=(x+\frac{1}{2})^{2}+\frac{3}{4}[/tex]

Learn more:

You can learn more about the quadratic functions in brainly.com/question/9390381

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Answer:

C

Step-by-step explanation: