Question

the expression π(r-3)^2 represents the area covered by the hour hand on a clock in one rotation, where r is the radius of the entire clock. Write a polynomial that represents the area covered by the hour hand in one rotation.

i've been stuck on this problem forever......

Answer 1

First, you have to square (r-3), which is (r-3)(r-3). You would then FOIL to get r^2-6r+9. You can't forget about pi, though; your actual expression at this point is pi(r^2-6r+9). You can then distribute pi to each term to get a final answer of pi(r^2)-6(pi)r+9(pi). (I had to use parenthesis there to make it look less confusing, as I don't have a pi symbol on my keyboard.)