Polynomial Remainder: (3x^3 - 2x^2 + 4x - 3) / (x^2 + 3x + 3)

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Finding the Remainder: Polynomial Division Explained

Hey guys! Let's dive into a fun math problem today: How do we figure out the remainder when we divide the polynomial 3x3−2x2+4x−3{3x^3 - 2x^2 + 4x - 3} by x2+3x+3{x^2 + 3x + 3}? This might sound intimidating, but don't worry, we'll break it down step by step. Polynomial division is a fundamental concept in algebra, and mastering it opens doors to solving various mathematical problems. It's not just about crunching numbers; it's about understanding the structure of polynomials and how they interact with each other. We'll explore the long division method, which is the most common technique for dividing polynomials, and also touch upon the Remainder Theorem, which provides a shortcut for finding remainders in certain cases. Understanding these methods will empower you to tackle complex polynomial problems with confidence and precision. So, let's get started and unlock the secrets of polynomial division!

Long Division: The Step-by-Step Approach

The key to solving this lies in using polynomial long division. Think of it like regular long division with numbers, but now we're dealing with expressions involving 'x'. Let's walk through it:

  1. Set up the division: Write the dividend (3x3−2x2+4x−3{3x^3 - 2x^2 + 4x - 3}) inside the division symbol and the divisor (x2+3x+3{x^2 + 3x + 3}) outside.

  2. Divide the leading terms: Focus on the highest power terms. What do you need to multiply x2{x^2} by to get 3x3{3x^3}? The answer is 3x{3x}. Write 3x{3x} above the division symbol, aligned with the x{x} term.

  3. Multiply: Multiply the entire divisor (x2+3x+3{x^2 + 3x + 3}) by 3x{3x}. This gives us 3x3+9x2+9x{3x^3 + 9x^2 + 9x}.

  4. Subtract: Subtract the result from the dividend. Remember to change the signs of the terms you're subtracting:

    (3x3−2x2+4x−3)−(3x3+9x2+9x)=−11x2−5x−3{(3x^3 - 2x^2 + 4x - 3) - (3x^3 + 9x^2 + 9x) = -11x^2 - 5x - 3}

  5. Bring down the next term: There are no more terms to bring down in this specific step, but in larger problems, you would bring down the next term from the original dividend.

  6. Repeat: Now, we focus on the new expression −11x2−5x−3{-11x^2 - 5x - 3}. What do you need to multiply x2{x^2} by to get −11x2{-11x^2}? The answer is -11. Write -11 above the division symbol, aligned with the constant term.

  7. Multiply: Multiply the divisor (x2+3x+3{x^2 + 3x + 3}) by -11. This gives us −11x2−33x−33{-11x^2 - 33x - 33}.

  8. Subtract: Subtract this result:

    (−11x2−5x−3)−(−11x2−33x−33)=28x+30{(-11x^2 - 5x - 3) - (-11x^2 - 33x - 33) = 28x + 30}

  9. Remainder: We've reached a point where the degree of the remaining expression (28x+30{28x + 30}) is less than the degree of the divisor (x2+3x+3{x^2 + 3x + 3}). This means 28x+30{28x + 30} is our remainder. Long division is a powerful tool for dividing polynomials, but it can be a bit tedious, especially with higher-degree polynomials. The key is to stay organized and follow the steps carefully. Each step builds upon the previous one, and a small mistake can throw off the entire calculation. So, practice makes perfect! The more you practice polynomial long division, the more comfortable and efficient you'll become. You'll start to recognize patterns and anticipate the next steps, making the process smoother and less daunting. Remember, it's not just about getting the right answer; it's about understanding the underlying principles of polynomial division.

The Remainder Theorem: A Quick Shortcut

While long division is the standard method, the Remainder Theorem offers a shortcut in some cases. It states that if you divide a polynomial f(x){f(x)} by x−a{x - a}, the remainder is f(a){f(a)}. However, this theorem directly applies when dividing by a linear factor (of the form x−a{x - a}). In our case, we're dividing by a quadratic, so the Remainder Theorem isn't a direct shortcut here. The Remainder Theorem is a powerful tool for finding remainders quickly, but it's important to understand its limitations. It's specifically designed for linear divisors, and using it with higher-degree divisors requires a different approach. However, the Remainder Theorem can be used in conjunction with other techniques, such as synthetic division, to solve more complex problems. For example, if you can factor the divisor into linear factors, you can apply the Remainder Theorem sequentially to find the remainder. This combination of techniques can significantly simplify the process of finding remainders, especially in more advanced problems. So, while the Remainder Theorem might not be a direct solution in every case, it's a valuable tool to have in your mathematical arsenal.

Conclusion: Our Remainder Revealed

Therefore, the remainder when 3x3−2x2+4x−3{3x^3 - 2x^2 + 4x - 3} is divided by x2+3x+3{x^2 + 3x + 3} is 28x+30{28x + 30}. So the answer is (D).

Polynomial division might seem daunting at first, but like any mathematical skill, it becomes easier with practice. The process involves breaking down the problem into smaller, manageable steps, and understanding the logic behind each step. The more you practice, the more comfortable you'll become with the process, and the faster you'll be able to solve these problems. Remember, math isn't just about memorizing formulas and procedures; it's about developing problem-solving skills and critical thinking. By mastering polynomial division, you're not just learning a mathematical technique; you're also sharpening your ability to approach complex problems in a systematic and logical way. So, keep practicing, keep exploring, and keep challenging yourself, and you'll be amazed at how far you can go in the world of mathematics!