How to do ii)
Deduce A^-1 = A^2 based on A^3=I

Multiply by on the right of both sides of , then use the fact that matrix multiplication is associative.

If , then

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.

if i put something wrong your not gonna like it so rather not say nothing.