Question

36 multiple choice 2 points if the area of a circle, a, is given as a function of its radius: a = πr², evaluate a(3in).

Explanation:

Step1: Substitute the value of radius

Given the formula \(A = \pi r^{2}\), substitute \(r = 3\) into the formula.
So, \(A(3)=\pi\times(3)^{2}\)

Step2: Calculate the result

First, calculate \((3)^{2}=9\). Then \(A(3)=\pi\times9 = 9\pi\) (square inches). If we take \(\pi\approx3.14\), then \(A(3)=9\times3.14 = 28.26\) (square inches)

Answer:

If we use the exact value: \(9\pi\) square inches. If we use \(\pi\approx3.14\): \(28.26\) square inches.