The design for a rectangular solid shipping container has a volume of 24x^3+6x^2-9x

1 answer

To work with the given volume of the rectangular solid shipping container \( V(x) = 24x^3 + 6x^2 - 9x \), we can perform several operations such as factoring or analyzing the expression to understand more about its dimensions.

Step 1: Factor the volume expression

We can start by factoring the polynomial \( V(x) \).

  1. Factor out the greatest common factor (GCF): The GCF of the terms \( 24x^3, 6x^2, \) and \( -9x \) is \( 3x \). So, we factor out \( 3x \):

    \[ V(x) = 3x(8x^2 + 2x - 3) \]

  2. Factor the quadratic \( 8x^2 + 2x - 3 \): We can factor the quadratic trinomial \( 8x^2 + 2x - 3 \) further. We look for two numbers that multiply to \( 8 \times -3 = -24 \) and add up to \( 2 \).

    The pairs of factors of \( -24 \) that add to \( 2 \) are \( 6 \) and \( -4 \).

    We can re-write the quadratic: \[ 8x^2 + 6x - 4x - 3 \]

    Group the terms: \[ = (8x^2 + 6x) + (-4x - 3) \] \[ = 2x(4x + 3) - 1(4x + 3) \] \[ = (2x - 1)(4x + 3) \]

Final Factorization

Putting all of this together, we can express \( V(x) \) as: \[ V(x) = 3x(2x - 1)(4x + 3) \]

Step 2: Interpret the dimensions

Since \( V(x) \) represents the volume of a rectangular solid, we can interpret \( 3x, (2x - 1), \) and \( (4x + 3) \) as the three dimensions \( l, w, h \) of the rectangular solid:

  • One dimension could be \( 3x \)
  • The second could be \( 2x - 1 \)
  • The third could be \( 4x + 3 \)

Step 3: Conditions for dimensions to be valid

For physical dimensions, the expressions for width and height must be positive:

  1. For \( 3x > 0 \): \( x > 0 \)
  2. For \( 2x - 1 > 0 \): \( x > \frac{1}{2} \)
  3. For \( 4x + 3 > 0 \): This is always true for \( x > 0 \) since \( 4x + 3 \) will always be positive.

Conclusion

The conditions determine that \( x \) needs to be greater than \( \frac{1}{2} \) for all dimensions to remain positive. The volume is factored as \( V(x) = 3x(2x - 1)(4x + 3) \), which gives us insight into the dimensions of the shipping container.