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F(x) = x2 + 6x + 4
What is the increasing and decreasing

User Francoise
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Answer:

  • decreasing: (-∞, -3)
  • increasing: (-3, ∞)

Explanation:

The leading coefficient is positive, so you know the parabola opens upward.

The ratio -b/(2a) is -6/(2·1) = -3, so you know the axis of symmetry is x = -3. The function will be decreasing from negative infinity to the vertex at x = -3, and will be increasing from there to positive infinity. At the vertex (x=-3), the function is neither increasing nor decreasing.

  • decreasing: (-∞, -3)
  • increasing: (-3, ∞)

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Additional comment

For ax^2 +bx +c, the axis of symmetry is x=-b/(2a). The vertex (turning point) is on the axis of symmetry.

F(x) = x2 + 6x + 4 What is the increasing and decreasing-example-1
User Mantosh Kumar
by
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