Complete the square to determine the minimum or maximum value of the function defined by the expression.

x2 + 4x + 3
A) maximum value at 1
B) minimum value at 1
C) maximum value at −1
D) minimum value at −1

Respuesta :

The minimum value at -1D

Step-by-step explanation:

The completing square form of ax² + bx + c is a(x - h)² + k, where

  • [tex]h=\frac{-b}{2a}[/tex]
  • k is the value of of the expression when x = h
  • k is minimum if a > 0 and maximum if a < 0

∵ The expression is x² + 4x + 3

∴ a = 1 , b = 4 , c = 3

- Use the rule above to find h

∵ [tex]h=\frac{-4}{2(1)}[/tex]

∴ h = -2

- To find k substitute x by the value of h

∵ k = (-2)² + 4(-2) + 3 = 4 - 8 + 3

∴ k = -1

- Substitute h and k in the form of the completing square

∵ a(x - h)² + k = 1(x - -2)² + (-1)

∴ a(x - h)² + k = (x + 2)² - 1

∴ x² + 4x + 3 = (x + 2)² - 1

∵ The completing square is (x + 2)² - 1

∵ a = 1 ⇒ greater than zero

∴ The value is minimum

- The minimum value is the value of k

∵ k = -1

∴ The minimum value of the function is -1

The minimum value at -1

Learn more:

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

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