Math Problem Statement

Determine whether there is a minimum or maximum value to the quadratic function h(t) = -4t^2 + 2t - 1. Find the minimum or maximum value and the axis of symmetry.

Solution

The quadratic function given is:

h(t)=4t2+2t1h(t) = -4t^2 + 2t - 1

Maximum or Minimum:

  • Since the coefficient of t2t^2 is negative (−4), the parabola opens downward, meaning the function has a maximum value.

Maximum Value:

The maximum value occurs at the vertex of the parabola. The formula for the vertex of a quadratic function at2+bt+cat^2 + bt + c is:

t=b2at = -\frac{b}{2a}

For h(t)=4t2+2t1h(t) = -4t^2 + 2t - 1, a=4a = -4 and b=2b = 2. Plugging these values into the vertex formula:

t=22(4)=28=14t = -\frac{2}{2(-4)} = \frac{2}{8} = \frac{1}{4}

So, the axis of symmetry is t=14t = \frac{1}{4}.

Finding the Maximum Value of hh:

Now, substitute t=14t = \frac{1}{4} back into the function to find the maximum value:

h(14)=4(14)2+2(14)1h\left(\frac{1}{4}\right) = -4\left(\frac{1}{4}\right)^2 + 2\left(\frac{1}{4}\right) - 1 h(14)=4(116)+121h\left(\frac{1}{4}\right) = -4\left(\frac{1}{16}\right) + \frac{1}{2} - 1 h(14)=416+121h\left(\frac{1}{4}\right) = -\frac{4}{16} + \frac{1}{2} - 1 h(14)=14+121=1+244=34h\left(\frac{1}{4}\right) = -\frac{1}{4} + \frac{1}{2} - 1 = \frac{-1 + 2 - 4}{4} = \frac{-3}{4}

Thus, the maximum value of hh is −3/4, which you correctly found.

Axis of Symmetry:

The axis of symmetry is t=14t = \frac{1}{4}, which should be the correct answer.

Would you like any additional details or clarification on this?

Here are five related questions to consider:

  1. How would you find the vertex of a quadratic function that opens upward?
  2. What is the significance of the discriminant in determining the number of real roots of a quadratic function?
  3. How does the coefficient of t2t^2 affect the direction of the parabola?
  4. How can we solve for the x-intercepts of this quadratic function?
  5. What are some real-world applications of finding the maximum or minimum of a quadratic function?

Tip: Always check the sign of the quadratic term (aa) to determine if the parabola opens upwards (minimum) or downwards (maximum).

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Math Problem Analysis

Mathematical Concepts

Algebra
Quadratic Functions
Parabolas

Formulas

Axis of Symmetry: t = -b / 2a
Maximum/Minimum Value: Vertex of the parabola

Theorems

Vertex formula for a quadratic function
Quadratic function symmetry

Suitable Grade Level

Grades 9-11