The volume of a cylinder is represented by the polynomial 2x^3 + 5x^2 + 3x + 18. The height of the cylinder is represented by the polynomial x + 3 What expression represents the area of the base of the cylinder?

1 answer

To find the expression for the area of the base of the cylinder, we can use the formula for the volume of a cylinder:

\[ \text{Volume} = \text{Base Area} \times \text{Height} \]

In this case, we know the following:

  • The volume of the cylinder is given by the polynomial \( V = 2x^3 + 5x^2 + 3x + 18 \).
  • The height of the cylinder is given by the polynomial \( h = x + 3 \).

We can express the area of the base, \( A \), as follows:

\[ A = \frac{V}{h} = \frac{2x^3 + 5x^2 + 3x + 18}{x + 3} \]

Now, we need to perform polynomial long division to divide \( 2x^3 + 5x^2 + 3x + 18 \) by \( x + 3 \).

  1. Divide the leading term:

    • First, divide \( 2x^3 \) by \( x \) to get \( 2x^2 \).
  2. Multiply and subtract:

    • Multiply \( 2x^2 \) by \( x + 3 \): \[ 2x^2(x + 3) = 2x^3 + 6x^2 \]
    • Subtract this from the original polynomial: \[ (2x^3 + 5x^2 + 3x + 18) - (2x^3 + 6x^2) = (5x^2 - 6x^2) + 3x + 18 = -x^2 + 3x + 18 \]
  3. Repeat the process:

    • Now divide \( -x^2 \) by \( x \) to get \( -x \).
    • Multiply \( -x \) by \( x + 3 \): \[ -x(x + 3) = -x^2 - 3x \]
    • Subtract: \[ (-x^2 + 3x + 18) - (-x^2 - 3x) = 3x + 3x + 18 = 6x + 18 \]
  4. Repeat the process again:

    • Now divide \( 6x \) by \( x \) to get \( 6 \).
    • Multiply \( 6 \) by \( x + 3 \): \[ 6(x + 3) = 6x + 18 \]
    • Subtract: \[ (6x + 18) - (6x + 18) = 0 \]

Since we have a remainder of 0, the division is exact.

Thus, the area of the base of the cylinder is represented by the expression:

\[ A = 2x^2 - x + 6 \]

Therefore, the expression representing the area of the base of the cylinder is:

\[ \boxed{2x^2 - x + 6} \]