What is the difference of the polynomials?


A$1.3 t^3 - 0.2 t^2 - 6 t - 8$
B$0.7 t^3 - t^2 - 6 t - 8$
C$1.3 t^3 - t^2 + 6 t - 8$
D$0.7 t^3 - 0.2 t^2 - 6 t - 8$

Verified Answer :

  • The problem is missing the specific pair of polynomials to be subtracted from the list provided.
  • The difference of two polynomials is calculated by subtracting the coefficients of corresponding powers of \(t\).
  • Using the general formula \(P_i(t) - P_j(t) = (c_{3,i}-c_{3,j})t^3 + (c_{2,i}-c_{2,j})t^2 + (c_{1,i}-c_{1,j})t + (c_{0,i}-c_{0,j})\), one can determine the difference for any chosen pair.
  • Example differences calculated include \(P_1(t) - P_2(t) = 0.6t^3 + 0.8t^2\) and \(P_3(t) - P_4(t) = 0.6t^3 - 0.8t^2 + 12t\).

Explanation

  1. Analysis and Methodology

The problem asks for the difference of two polynomials selected from a provided list of four. However, the specific pair of polynomials to be subtracted is not explicitly stated. The polynomials provided are:

  1. \(P_1(t) = 1.3t^3 - 0.2t^2 - 6t - 8\)
  2. \(P_2(t) = 0.7t^3 - t^2 - 6t - 8\)
  3. \(P_3(t) = 1.3t^3 - t^2 + 6t - 8\)
  4. \(P_4(t) = 0.7t^3 - 0.2t^2 - 6t - 8\)

Given the missing specification, the objective is to demonstrate the method for calculating the difference between any two polynomials \(P_i(t)\) and \(P_j(t)\) from this list. To subtract two polynomials, we subtract the coefficients of corresponding powers of \(t\). For example, if we want to calculate \(P_i(t) - P_j(t)\), we group the terms by the power of \(t\).

  1. Example Calculation: \(P_1(t) - P_2(t)\)

To illustrate the process, we will calculate the difference between the first and second polynomials, \(P_1(t) - P_2(t)\):
\(P_1(t) - P_2(t) = (1.3t^3 - 0.2t^2 - 6t - 8) - (0.7t^3 - t^2 - 6t - 8)\)
Grouping the coefficients by powers of \(t\):
\(= (1.3 - 0.7)t^3 + (-0.2 - (-1))t^2 + (-6 - (-6))t + (-8 - (-8))\)
Calculating the differences of the coefficients:
\(= (0.6)t^3 + (-0.2 + 1)t^2 + (-6 + 6)t + (-8 + 8)\)
\(= 0.6t^3 + 0.8t^2 + 0t + 0\)
\(= 0.6t^3 + 0.8t^2\)
This result shows how the constant and linear terms can cancel out depending on the chosen polynomials.

  1. General Method and Conclusion

As another example, let us consider the difference between \(P_3(t)\) and \(P_4(t)\):
\(P_3(t) - P_4(t) = (1.3t^3 - t^2 + 6t - 8) - (0.7t^3 - 0.2t^2 - 6t - 8)\)
Grouping the terms:
\(= (1.3 - 0.7)t^3 + (-1 - (-0.2))t^2 + (6 - (-6))t + (-8 - (-8))\)
Calculating the differences:
\(= 0.6t^3 + (-1 + 0.2)t^2 + (6 + 6)t + 0\)
\(= 0.6t^3 - 0.8t^2 + 12t\)
These examples demonstrate how the operation is performed systematically by aligning like terms. For any pair \(P_i(t)\) and \(P_j(t)\), the difference is found by performing the subtraction \((c_{3,i}-c_{3,j})t^3 + (c_{2,i}-c_{2,j})t^2 + (c_{1,i}-c_{1,j})t + (c_{0,i}-c_{0,j})\), where \(c_{k,n}\) is the coefficient of \(t^k\) in polynomial \(n\). The final result depends entirely on the chosen pair of polynomials. Since no specific pair was requested, the general method provides the solution.

Examples

Polynomial subtraction is a fundamental operation used in various fields, such as engineering and physics, to determine the error between an estimated model and a real-world measurement. For instance, if a designer has two different models for the trajectory of a rocket, represented by polynomials \(P_1(t)\) and \(P_2(t)\), subtracting them (\(P_1(t) - P_2(t)\)) reveals how the predicted paths deviate over time. Understanding how to align and subtract these coefficients ensures that the comparison between models is accurate, allowing for better predictive analysis and design adjustments.