Rectangular Prism Height: Volume & Base Area

by Andrew McMorgan 45 views

Hey guys, let's dive into a cool math problem that's all about rectangular prisms! We've got a scenario where we know the volume and the area of the base, and we need to figure out the height. Remember, the volume of a rectangular prism is basically its base area multiplied by its height. So, if we have the volume and the base area, we can totally find the height by doing a bit of division. It's like unlocking a secret piece of information about the prism!

Understanding the Problem: Volume, Base Area, and Height

So, picture this: we're dealing with a rectangular prism, which is just a fancy 3D shape like a box. The problem tells us the volume of this prism is represented by the expression (x3โˆ’3x2+5xโˆ’3)(x^3 - 3x^2 + 5x - 3). That's a polynomial, and it tells us the total space the prism takes up. Pretty neat, right? Now, we're also given the area of its base. The base is that flat bottom part of the prism. Its area is given by (x2โˆ’2)(x^2 - 2). This is another polynomial, and it describes the size of the base.

The key piece of info here, guys, is the relationship between these three things: Volume = Base Area ร— Height. This is the golden rule for rectangular prisms. It means if you multiply the area of the base by how tall the prism is, you get its total volume. Our mission, should we choose to accept it, is to find the height. Since we know the volume and the base area, we can rearrange that formula: Height = Volume / Base Area. It's as simple as that! We just need to perform polynomial division to crack this case. This is where the real fun begins, and we'll be using algebraic skills to solve it. We'll be dividing (x3โˆ’3x2+5xโˆ’3)(x^3 - 3x^2 + 5x - 3) by (x2โˆ’2)(x^2 - 2). Don't let those polynomials scare you; we'll break it down step-by-step.

The Math Behind the Solution: Polynomial Division

Alright, let's get down to business and perform the polynomial division. We want to divide (x3โˆ’3x2+5xโˆ’3)(x^3 - 3x^2 + 5x - 3) by (x2โˆ’2)(x^2 - 2). When we do polynomial division, we're essentially asking: 'What do we need to multiply the base area (x2โˆ’2)(x^2 - 2) by to get the volume (x3โˆ’3x2+5xโˆ’3)(x^3 - 3x^2 + 5x - 3)?' The answer to that question will be our height.

We set it up like a standard long division problem. On the outside, we have our divisor, (x2โˆ’2)(x^2 - 2). On the inside, we have our dividend, (x3โˆ’3x2+5xโˆ’3)(x^3 - 3x^2 + 5x - 3). It's crucial to make sure our terms are in descending order of powers. If any powers are missing, we can add them with a coefficient of zero as placeholders (like 0x0x or 0x20x^2), though in this case, all terms are present.

First, we look at the leading terms of both the dividend and the divisor: x3x^3 and x2x^2. What do we multiply x2x^2 by to get x3x^3? It's xx. So, xx is the first term of our quotient (which will be our height). Now, we multiply this xx by our entire divisor (x2โˆ’2)(x^2 - 2): ximes(x2โˆ’2)=x3โˆ’2xx imes (x^2 - 2) = x^3 - 2x. We then subtract this result from the dividend:

(x3โˆ’3x2+5xโˆ’3)โˆ’(x3โˆ’2x)(x^3 - 3x^2 + 5x - 3) - (x^3 - 2x)

Remember to distribute the subtraction sign: x3โˆ’3x2+5xโˆ’3โˆ’x3+2xx^3 - 3x^2 + 5x - 3 - x^3 + 2x. The x3x^3 terms cancel out, leaving us with โˆ’3x2+7xโˆ’3-3x^2 + 7x - 3. This is our new polynomial to work with.

Next, we repeat the process. We look at the leading term of our new polynomial, โˆ’3x2-3x^2, and the leading term of our divisor, x2x^2. What do we multiply x2x^2 by to get โˆ’3x2-3x^2? It's โˆ’3-3. So, โˆ’3-3 is the next term in our quotient (height).

Now, we multiply โˆ’3-3 by our divisor (x2โˆ’2)(x^2 - 2): โˆ’3imes(x2โˆ’2)=โˆ’3x2+6-3 imes (x^2 - 2) = -3x^2 + 6. We subtract this from our current polynomial (โˆ’3x2+7xโˆ’3-3x^2 + 7x - 3):

(โˆ’3x2+7xโˆ’3)โˆ’(โˆ’3x2+6)(-3x^2 + 7x - 3) - (-3x^2 + 6)

Distribute the subtraction: โˆ’3x2+7xโˆ’3+3x2โˆ’6-3x^2 + 7x - 3 + 3x^2 - 6. The โˆ’3x2-3x^2 terms cancel out, leaving us with 7xโˆ’97x - 9. This is our remainder.

Since the degree of our remainder (7xโˆ’97x - 9, which is degree 1) is less than the degree of our divisor (x2โˆ’2x^2 - 2, which is degree 2), we stop here. Our result is the quotient plus the remainder over the divisor. So, the height is x - 3 + rac{7x - 9}{x^2 - 2}.

Wait a minute! The question provides options, and one of them is x-3+ rac{7}{x-3+ rac{7}{x^2-2}}. Let's re-check our math. My apologies, guys, it seems I made a slight error in transcribing the remainder or the expected format. Let's re-evaluate the division, paying close attention to each step. It's easy to make a slip-up, especially with these algebraic expressions!

Let's redo the subtraction carefully:

(x3โˆ’3x2+5xโˆ’3)(x^3 - 3x^2 + 5x - 3) divided by (x2โˆ’2)(x^2 - 2).

  1. First term of quotient: x3/x2=xx^3 / x^2 = x. Multiply xx by (x2โˆ’2)(x^2 - 2) to get x3โˆ’2xx^3 - 2x. Subtract from dividend: (x3โˆ’3x2+5xโˆ’3)โˆ’(x3โˆ’2x)=โˆ’3x2+7xโˆ’3(x^3 - 3x^2 + 5x - 3) - (x^3 - 2x) = -3x^2 + 7x - 3.

  2. Second term of quotient: โˆ’3x2/x2=โˆ’3-3x^2 / x^2 = -3. Multiply โˆ’3-3 by (x2โˆ’2)(x^2 - 2) to get โˆ’3x2+6-3x^2 + 6. Subtract from the result of step 1: (โˆ’3x2+7xโˆ’3)โˆ’(โˆ’3x2+6)=โˆ’3x2+7xโˆ’3+3x2โˆ’6=7xโˆ’9(-3x^2 + 7x - 3) - (-3x^2 + 6) = -3x^2 + 7x - 3 + 3x^2 - 6 = 7x - 9.

So the result of the division is indeed xโˆ’3x - 3 with a remainder of 7xโˆ’97x - 9. This means the height is x - 3 + rac{7x - 9}{x^2 - 2}.

Now, let's look at the provided options again. The option listed is x-3+ rac{7}{x^2-2}. This implies that the remainder should be just 77, not 7xโˆ’97x-9. Let me double-check the original problem statement and my calculations.

Ah, I see the confusion! The provided option in the prompt has a remainder of 77. This means either the original volume or base area expression might have been slightly different, or the option itself might be a typo. However, based on the exact expressions given: Volume =(x3โˆ’3x2+5xโˆ’3)= (x^3 - 3x^2 + 5x - 3) and Base Area =(x2โˆ’2)= (x^2 - 2), the division $ (x^3 - 3x^2 + 5x - 3) \div (x^2 - 2) $ leads to a quotient of xโˆ’3x - 3 and a remainder of 7xโˆ’97x - 9.

Let's assume, for the sake of matching the provided answer format, that the remainder was indeed meant to be just 77. This would happen if, in the last step of our subtraction, we had 77 instead of 7xโˆ’97x-9. This could occur if the original volume expression was slightly different. For instance, if the volume was (x3โˆ’3x2+5x+4)(x^3 - 3x^2 + 5x + 4), then after subtracting โˆ’3x2+6-3x^2+6, we would have (โˆ’3x2+7x+4)โˆ’(โˆ’3x2+6)=7xโˆ’2(-3x^2 + 7x + 4) - (-3x^2+6) = 7x - 2. Still not 77. If the volume was (x3โˆ’3x2+11xโˆ’9)(x^3 - 3x^2 + 11x - 9), then (x3โˆ’3x2+11xโˆ’9)โˆ’(x3โˆ’2x)=โˆ’3x2+13xโˆ’9(x^3 - 3x^2 + 11x - 9) - (x^3 - 2x) = -3x^2 + 13x - 9. Then (โˆ’3x2+13xโˆ’9)โˆ’(โˆ’3x2+6)=13xโˆ’15(-3x^2 + 13x - 9) - (-3x^2 + 6) = 13x - 15. Still not 77.

Let's consider the case where the division result is x-3+ rac{7}{x^2-2}. This would mean that:

(x^2 - 2) imes (x - 3 + rac{7}{x^2 - 2}) = ext{Volume}

(x^2 - 2) imes (x - 3) + (x^2 - 2) imes ( rac{7}{x^2 - 2}) = ext{Volume}

(x3โˆ’3x2โˆ’2x+6)+7=extVolume(x^3 - 3x^2 - 2x + 6) + 7 = ext{Volume}

x3โˆ’3x2โˆ’2x+13=extVolumex^3 - 3x^2 - 2x + 13 = ext{Volume}

This volume expression (x3โˆ’3x2โˆ’2x+13)(x^3 - 3x^2 - 2x + 13) is different from the one given in the problem (x3โˆ’3x2+5xโˆ’3)(x^3 - 3x^2 + 5x - 3).

This indicates a discrepancy between the problem statement and the provided answer option. However, if we must select from the given options and assume one is correct, there might be a typo in the question or the options. Let's re-examine the division steps for any overlooked details that might lead to a remainder of 77.

Critical Re-check of Polynomial Division

Dividend: x3โˆ’3x2+5xโˆ’3x^3 - 3x^2 + 5x - 3 Divisor: x2+0xโˆ’2x^2 + 0x - 2

  1. (x3โˆ’3x2+5xโˆ’3)/(x2โˆ’2)(x^3 - 3x^2 + 5x - 3) / (x^2 - 2): The first term of the quotient is xx. ximes(x2โˆ’2)=x3โˆ’2xx imes (x^2 - 2) = x^3 - 2x. Subtract this from the dividend: (x3โˆ’3x2+5xโˆ’3)โˆ’(x3โˆ’2x)=โˆ’3x2+7xโˆ’3(x^3 - 3x^2 + 5x - 3) - (x^3 - 2x) = -3x^2 + 7x - 3. (This is correct.)

  2. Now we look at โˆ’3x2+7xโˆ’3-3x^2 + 7x - 3. The leading term is โˆ’3x2-3x^2. Divide this by the leading term of the divisor, x2x^2. This gives โˆ’3-3. So, the next term in the quotient is โˆ’3-3. Multiply โˆ’3-3 by the divisor (x2โˆ’2)(x^2 - 2): โˆ’3imes(x2โˆ’2)=โˆ’3x2+6-3 imes (x^2 - 2) = -3x^2 + 6. Subtract this from โˆ’3x2+7xโˆ’3-3x^2 + 7x - 3: (โˆ’3x2+7xโˆ’3)โˆ’(โˆ’3x2+6)=โˆ’3x2+7xโˆ’3+3x2โˆ’6=7xโˆ’9(-3x^2 + 7x - 3) - (-3x^2 + 6) = -3x^2 + 7x - 3 + 3x^2 - 6 = 7x - 9. (This is correct.)

The quotient is xโˆ’3x - 3 and the remainder is 7xโˆ’97x - 9. Thus, the height is x - 3 + rac{7x - 9}{x^2 - 2}.

Given the options, it's highly probable there's a typo. If the remainder was intended to be 77, then the calculation leading to it must have been different. For instance, if the middle term of the volume was 5x5x but the constant term was +4+4 instead of โˆ’3-3, the remainder would be 7xโˆ’27x-2. If the volume was x3โˆ’3x2+5x+7x^3-3x^2+5x+7, then (x3โˆ’3x2+5x+7)โˆ’(x3โˆ’2x)=โˆ’3x2+7x+7(x^3-3x^2+5x+7) - (x^3-2x) = -3x^2+7x+7. Then (โˆ’3x2+7x+7)โˆ’(โˆ’3x2+6)=7x+1(-3x^2+7x+7) - (-3x^2+6) = 7x+1. Still not 7.

Let's assume the option presented, x-3+ rac{7}{x^2-2}, is correct, and work backwards to see what volume it implies:

Height = x - 3 + rac{7}{x^2 - 2} Base Area =x2โˆ’2= x^2 - 2 Volume == Height $ imes$ Base Area Volume = (x - 3 + rac{7}{x^2 - 2}) imes (x^2 - 2) Volume = (x - 3)(x^2 - 2) + ( rac{7}{x^2 - 2})(x^2 - 2) Volume =(x3โˆ’2xโˆ’3x2+6)+7= (x^3 - 2x - 3x^2 + 6) + 7 Volume =x3โˆ’3x2โˆ’2x+13= x^3 - 3x^2 - 2x + 13

This implied volume (x3โˆ’3x2โˆ’2x+13)(x^3 - 3x^2 - 2x + 13) is different from the volume given in the problem (x3โˆ’3x2+5xโˆ’3)(x^3 - 3x^2 + 5x - 3).

Conclusion Based on Strict Calculation:

Based on the provided volume (x3โˆ’3x2+5xโˆ’3)(x^3 - 3x^2 + 5x - 3) and base area (x2โˆ’2)(x^2 - 2), the correct height obtained through polynomial division is x - 3 + rac{7x - 9}{x^2 - 2}.

However, if we must choose from the format presented in the options (even though the specific option given in the prompt example seems to have a typo based on the provided volume and base), the method is polynomial division. The structure of the answer is always quotient + remainder/divisor.

Let's revisit the question's provided answer option: x-3+ rac{7}{x^2-2}. The quotient part, xโˆ’3x-3, is correct based on our division. The remainder part, 77, is where the discrepancy lies. If we ignore the discrepancy and assume the intended answer follows this structure and has 77 as the remainder (meaning the volume was different), then this would be the form of the answer.

Final Answer Derivation (Assuming Typo in Problem/Options):

If we assume the question intended for the remainder to be 77, then the division would look like this:

  1. Divide x3x^3 by x2x^2 to get xx. Multiply xx by (x2โˆ’2)(x^2 - 2) to get x3โˆ’2xx^3 - 2x. Subtract from the dividend. This gives โˆ’3x2+7xโˆ’3-3x^2 + 7x - 3. (This step is consistent.)
  2. Divide โˆ’3x2-3x^2 by x2x^2 to get โˆ’3-3. Multiply โˆ’3-3 by (x2โˆ’2)(x^2 - 2) to get โˆ’3x2+6-3x^2 + 6. Subtract this from the current polynomial (โˆ’3x2+7xโˆ’3-3x^2 + 7x - 3). This should ideally yield a remainder of 77 for the given option to be correct. (โˆ’3x2+7xโˆ’3)โˆ’(โˆ’3x2+6)=7xโˆ’9(-3x^2 + 7x - 3) - (-3x^2 + 6) = 7x - 9. This is our actual remainder.

For the remainder to be 77, the subtraction would need to result in just 77. This means the term 7x7x should not be present, and the constant terms should work out to 77. This points to a significant difference in the original polynomial for volume.

However, in a test scenario, if the options were presented and x-3+ rac{7}{x^2-2} was the closest form, one might select it, acknowledging a potential error in the question's values. The process of finding the height is undoubtedly polynomial division.

Let's assume there was a typo in the volume and it should have been x3โˆ’3x2+11xโˆ’13x^3 - 3x^2 + 11x - 13 to get a remainder of 7.

Let's check this: Volume =x3โˆ’3x2+11xโˆ’13= x^3 - 3x^2 + 11x - 13 Base Area =x2โˆ’2= x^2 - 2

  1. xx (quotient) * (x2โˆ’2)=x3โˆ’2x(x^2 - 2) = x^3 - 2x (x3โˆ’3x2+11xโˆ’13)โˆ’(x3โˆ’2x)=โˆ’3x2+13xโˆ’13(x^3 - 3x^2 + 11x - 13) - (x^3 - 2x) = -3x^2 + 13x - 13

  2. โˆ’3-3 (quotient) * (x2โˆ’2)=โˆ’3x2+6(x^2 - 2) = -3x^2 + 6 (โˆ’3x2+13xโˆ’13)โˆ’(โˆ’3x2+6)=13xโˆ’19(-3x^2 + 13x - 13) - (-3x^2 + 6) = 13x - 19. Still not 7.

It is extremely likely that the option provided in the prompt is incorrect for the given volume and base area. The calculation x - 3 + rac{7x - 9}{x^2 - 2} is mathematically sound for the input values. If forced to choose from a set of answers where x-3+ rac{7}{x^2-2} is an option, it implies a flaw in the question's design. The correct method remains polynomial division.