Question

A cubical box has a side-length of 1m. It is placed next to a wall which is perpendicular to the ground. A ladder 4.9 meters long is placed so that it rests against the ground, the and an edge of the box as shown in the diagram.

Answer 1

Let xm and ym be the lengths of AB and AC respectively
a. find BD in tems of x
b. find CF in terms of y
c. prove that /\ DBE is similar to /\ FEC. Hence show that xy=x+y
d. prove that x2 + y2=24
e. use parts c and d to prove that (y+y)2 - 2(x+y)-24=0
f. at what height does the ladder rest against the wall?
g. does f have more than one solution?

Answer 2

Not sure how to do it