How many books 2.5cm wide can fit on a shelf 1 metre wide

What is the equation of the parabola with focus (-1,-1) and directrix y=1?

What is the slopeof the live that passes through the points and (-2,-5) and (3,-1)

An observer(o) spots a plane(p) taking off from a local airport and flying at a 29 degree angle horizontal to her line of sight and located directly above a tower(t). the observer also notices a bird circling directly above her. if the distance from the plane(p) to the tower(t) is 6,000ft., how far is the bird(b) from the plane(p).