An electronic store averages 32 sales per day of Blu-ray players listed at $100 each said they indicates that for each five dollars decreasing price two more sales would curve the graph of the projected revenue in terms of the number of five dollar decreases shown starts off with 3200 has an increase of 3230 and another increase of 3240 goes back down to 3230 then again back down to 3200 and skyrocket skyrocket all the way down to 3150. Now identify the axis of symmetry and coordinates of the vertex the maximum revenue. The price at which the store would have maximum revenue, and the number of five dollars decreases that would produce no revenue.

1 answer

To analyze the revenue generated by Blu-ray player sales based on the provided information, we can follow these steps:

  1. Understanding the Revenue Function:

    • Let \( x \) be the number of five-dollar decreases in price.
    • The price of the Blu-ray player after \( x \) decreases is \( 100 - 5x \).
    • The number of sales after \( x \) decreases is given by \( 32 + 2x \).
    • Revenue \( R \) can be modeled with the equation: \[ R(x) = \text{(Price)} \times \text{(Sales)} = (100 - 5x)(32 + 2x) \]
    • Expanding this formula: \[ R(x) = (100)(32) + (200 - 5x*32) - (5x)(2x) = 3200 + 200x - 160x - 10x^2 = -10x^2 + 40x + 3200 \]
    • Thus, the revenue function is: \[ R(x) = -10x^2 + 40x + 3200 \]
  2. Finding the Vertex:

    • This function is a downward-opening parabola (as the coefficient of \( x^2 \) is negative).
    • The vertex gives the maximum revenue and can be found using the formula for the \( x \)-coordinate of the vertex: \[ x = -\frac{b}{2a} \]
    • Here, \( a = -10 \) and \( b = 40 \): \[ x = -\frac{40}{2(-10)} = \frac{40}{20} = 2 \]
    • So, \( x = 2 \).
  3. Coordinates of the Vertex (Maximum Revenue):

    • To find the maximum revenue, substitute \( x = 2 \) back into the revenue function: \[ R(2) = -10(2^2) + 40(2) + 3200 = -10(4) + 80 + 3200 \] \[ R(2) = -40 + 80 + 3200 = 3240 \]
    • The vertex is at \( (2, 3240) \), thus:
      • The coordinates of the vertex (maximum revenue) are \( (2, 3240) \).
  4. Price for Maximum Revenue:

    • The price at maximum revenue (when \( x = 2 \)): \[ P = 100 - 5(2) = 100 - 10 = 90 \]
    • The price for maximum revenue is $90.
  5. Determining No Revenue:

    • Revenue will be zero when: \[ R(x) = 0 \]
    • Solving for \( x \): \[ -10x^2 + 40x + 3200 = 0 \] \[ x^2 - 4x - 320 = 0 \]
    • Using the quadratic formula \( x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \): \[ x = \frac{-(-4) \pm \sqrt{(-4)^2 - 4(1)(-320)}}{2(1)} = \frac{4 \pm \sqrt{16 + 1280}}{2} = \frac{4 \pm \sqrt{1296}}{2} \] \[ x = \frac{4 \pm 36}{2} \]
      • This gives: \[ x = \frac{40}{2} = 20 \quad \text{and} \quad x = \frac{-32}{2} = -16 \text{ (not valid)} \]
    • Thus, the number of five-dollar decreases that would produce no revenue is \( x = 20 \).

Summary:

  • Axis of Symmetry: \( x = 2 \)
  • Coordinates of Vertex (Max Revenue): \( (2, 3240) \)
  • Price for Maximum Revenue: $90
  • Number of Five Dollar Decreases that Produce No Revenue: 20