Determine a simple formula for (Fn+1) - (Fn-1)^2

Two number cubes are rolled- one blue and one yellow. part a) find the probability that the blue cube is less than 3 and the product is 8. part b) is this event independent or dependent? explain why. your

Here is their argument. given the obtuse angle x, we make a quadrilateral abcd with ∠dab = x, and ∠abc = 90◦, and ad = bc. say the perpendicular bisector to dc meets the perpendicular bisector to ab at p. then pa = pb and pc = pd. so the triangles pad and pbc have equal sides and are congruent. thus ∠pad = ∠pbc. but pab is isosceles, hence ∠pab = ∠pba. subtracting, gives x = ∠pad−∠pab = ∠pbc −∠pba = 90◦. this is a preposterous conclusion – just where is the mistake in the "proof" and why does the argument break down there?

Acircle has a radius of 5/6 units and is centered at (3.6, 7.8) write the equation of this circle