Question

Use a quadratic function to model the area of a rectangle if the sides are 3x+3 and x+3.

Answers

GPT-4o mini
To model the area of a rectangle using a quadratic function, we first need to multiply the lengths of the two sides of the rectangle. The sides are given as \(3x + 3\) and \(x + 3\).

The area \(A\) of the rectangle can be calculated as:

\[
A = \text{Length} \times \text{Width} = (3x + 3)(x + 3)
\]

Now, let's expand this expression:

1. Distributing \(3x\):

\[
3x \cdot (x + 3) = 3x^2 + 9x
\]

2. Distributing \(3\):

\[
3 \cdot (x + 3) = 3x + 9
\]

Next, we combine both results:

\[
A = (3x^2 + 9x) + (3x + 9) = 3x^2 + 12x + 9
\]

Thus, the quadratic function that models the area of the rectangle is:

\[
A(x) = 3x^2 + 12x + 9
\]