Segma infinity to k=2 (k!)^2/(2k)! X^2k+1

These are geometric or telescoping series.) A. ∞. ∑ k=3. 5. 2k . ... k=3. 5. 2k. = 5. 23. +. 5. 24. +. 5. 25. + ···. This is a geometric series with ratio r = 1/2. ... 516) with f(x)=1/(x ln(x)).

18

step-by-step explanation:

draw the shape and you will see that f and k are actually at adjacent vertices (points of the hexagon that are neighboring).   so find the distance between (1,2) and (4,2).   that is easy since (1,2) and (4,2) is just a vertical distance to count, which is 3.   it is a regular polygon which means all sides are congruent.   you have 6 sides (hexa) so multiply 6 by 3 to receive 18.