Question

Express the area A of a circle as a function of its​ radius, r. Determine the area of a circle whose radius is 11 inches. That​ is, find ​A(11​). Express the area A of a circle as a function of its​ radius, r.

Answer 1

Answer with explanation:

The function represents the area of a circle(A) is given by :-

`A(r)=2\pi r`

To determine the area of a circle whose radius is 11 inches. , we put the value of r=11 inches, we get

`A(11)=2\pi (11)`

Now, we put
`\pi=(22)/(7)` in the above function , we get

`A(11)=2((22)/(7) )(11)\\\\\Rightarrow\ A=56.5714285714\approx56.57`