Need Help In These word problems

http://www.freeimagehosting.net/uploads/be68bfcc1d.jpg

Let Me know if u have any problem reading it.

Ok so for question 9 i got this

a:0 show swimming distance is given by relationd d=wsecx

cos x=w/d

d=w/cosx

d=wsecx

B:)

if l=2w determine the range of values that x may take on given that P can anywhere along the length of pool. so i tried these

cosx=w/d will not work

sinx=2w/d will not work

tanx=2w/w

tanx=2 inverse therefore

0<x<1.07, is this right?

C) im stuck in this question! please help any hints?

D) I think i know how to do once i figured out c?

E) same as D

For question 10, im just confused any hints is appreciated :D

Soln. to question 10 (a,b and d).

(10a) line d // horizontal. Hence x = angle on the top right in the triangle, since alternate angles are equal.

2/d =tanx

2/tanx=d

2cotx=d

(10b)

d=2/tanx

d=2/tan(pi/3)

d=1.15 metres

(10d)

Refer to the diagram in the question. When x approaches 0, then the window would get full sunlight (no shade). When x approaches pi/2, i.e. 90 degrees, then the window will get no sunlight (full shade). I hope this is correct.