8.49 x 10⁻⁷ = 0.000000849
If a circle has radius
R, its circumference equals to
2πR where π is an irrational number that, approximately, equals to
3.1415926
S = n(a1 + an)/2
2S = n(a1 + an)
2S = na1 + nan
nan = 2S - na1
an = (2S - n a1)/n
(B)
if <em>f</em>(a) = K, then that means <em>f </em>sends (a) to (K).
the inverse function, <em>f</em>-1, goes back where you started, so <em>f</em>-1 <em />sends (K) to (a).
<em>f</em>-1(K) = a.
The correct way is to plug in the answer back into the equation and see if it results in the correct solution.
