Find (f + g)(f - g)(f g)(f/g) for i) f(x) = 4x + 3, g(x) = 2x - 1 ii) f(x) = 2x^2, g(x) = x + 1.

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Understand the Problem

The question is asking to find the expression (f + g)(f - g)(f g)(f/g) for the given functions f(x) and g(x) provided in both parts i and ii. It requires performing algebraic operations on the functions to arrive at the final expression.

Answer

For part i: $$ (6x + 2)(2x + 4)(8x^2 + 2x - 3)\left(\frac{4x + 3}{2x - 1}\right) $$ For part ii: $$ (2x^2 + x + 1)(2x^2 - x - 1)(2x^3 + 2x^2)\left(\frac{2x^2}{x + 1}\right) $$
Answer for screen readers

For part i:
$$ (f + g)(f - g)(f \cdot g)(\frac{f}{g}) = (6x + 2)(2x + 4)(8x^2 + 2x - 3)\left(\frac{4x + 3}{2x - 1}\right) $$

For part ii:
$$ (f + g)(f - g)(f \cdot g)(\frac{f}{g}) = (2x^2 + x + 1)(2x^2 - x - 1)(2x^3 + 2x^2)\left(\frac{2x^2}{x + 1}\right) $$

Steps to Solve

  1. Evaluate for functions f and g
    For part i, we have:
    $$ f(x) = 4x + 3 $$
    $$ g(x) = 2x - 1 $$

For part ii:
$$ f(x) = 2x^2 $$
$$ g(x) = x + 1 $$

  1. Calculate ( f + g )
    For part i:
    $$ f + g = (4x + 3) + (2x - 1) = 6x + 2 $$

For part ii:
$$ f + g = (2x^2) + (x + 1) = 2x^2 + x + 1 $$

  1. Calculate ( f - g )
    For part i:
    $$ f - g = (4x + 3) - (2x - 1) = 2x + 4 $$

For part ii:
$$ f - g = (2x^2) - (x + 1) = 2x^2 - x - 1 $$

  1. Calculate ( f \cdot g )
    For part i:
    $$ f \cdot g = (4x + 3)(2x - 1) = 8x^2 - 4x + 6x - 3 = 8x^2 + 2x - 3 $$

For part ii:
$$ f \cdot g = (2x^2)(x + 1) = 2x^3 + 2x^2 $$

  1. Calculate ( \frac{f}{g} )
    For part i:
    $$ \frac{f}{g} = \frac{4x + 3}{2x - 1} $$

For part ii:
$$ \frac{f}{g} = \frac{2x^2}{x + 1} $$

  1. Combine all expressions
    For part i:
    $$ (f + g)(f - g)(f \cdot g)(\frac{f}{g}) = (6x + 2)(2x + 4)(8x^2 + 2x - 3)\left(\frac{4x + 3}{2x - 1}\right) $$

For part ii:
$$ (f + g)(f - g)(f \cdot g)(\frac{f}{g}) = (2x^2 + x + 1)(2x^2 - x - 1)(2x^3 + 2x^2)\left(\frac{2x^2}{x + 1}\right) $$

  1. Final Expression
    Calculate the final expressions for both parts accordingly.

For part i:
$$ (f + g)(f - g)(f \cdot g)(\frac{f}{g}) = (6x + 2)(2x + 4)(8x^2 + 2x - 3)\left(\frac{4x + 3}{2x - 1}\right) $$

For part ii:
$$ (f + g)(f - g)(f \cdot g)(\frac{f}{g}) = (2x^2 + x + 1)(2x^2 - x - 1)(2x^3 + 2x^2)\left(\frac{2x^2}{x + 1}\right) $$

More Information

The expressions derived in both parts involve a series of algebraic operations: addition, subtraction, multiplication, and division of polynomial functions. These kinds of problems illustrate the importance of algebra in manipulating functions.

Tips

  • Forgetting to distribute correctly when multiplying expressions, leading to incorrect coefficients.
  • Not simplifying fractions appropriately in ( \frac{f}{g} ).
  • Ignoring the signs while performing the operations, particularly in subtraction.

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