Posted by peter on .
A ladder 14 ft long rests against a vertical wall. Let \theta be the angle between the top of the ladder and the wall and let x be the distance from the bottom of the ladder to the wall. If the bottom of the ladder slides away from the wall, how fast does x change with respect to \theta when \theta = \pi / 3?

math 
Reiny,
sinØ = x/14
cosØ = (1/4)dx/dØ
dx/dØ = 4cosØ
so when Ø = π/3
dx/dØ = 4cosπ/3 = 2 
OOPS  math 
Reiny,
somehow my 14 changed to 4,
(need new specks)
so all the 4's are 14's
and last line is
dx/dØ = 14cos π/3 = 7 
OOPS#2  math 
Reiny,
just realized that drwls had already answered the question correctly,
http://www.jiskha.com/display.cgi?id=1272944003