The formula for the area of a circle is A=(pie)r^2. The area is a function of the radius. How do I write this using function notation and how do I determine the area when the radius is 17 yards?

Question

The formula for the area of a circle is A=(pie)r^2. The area is a function of the radius.  How do I write this using function notation and how do I determine the area when the radius is 17 yards?

anonymous · Answer

well, when the radius is 17 all you have to do is plug in 17 for r in the function:
A=(pie)(17)^2

anonymous · Answer

$$A(r)=\pi r^2$$ is function notation

anonymous · Answer

btw it is "pi" the greek letter, not "pie" the dessert.  just thought i would mention it

anonymous · Answer

Ok thanks, but how do I find the radius when it is 17 yards

anonymous · Answer

i just wrote it out for you

anonymous · Answer

$$A=\pi(17)^2$$

anonymous · Answer

what lagrange said.  square 17, multiply the result by pi