Saturday
December 20, 2014

Homework Help: trigo--help!

Posted by holly on Monday, March 12, 2007 at 2:51am.

how do i do this question?

a ladder length 13m rests against a vertical wall with its foot on a horizontal floor at a distance of 5m from the wall. when the top of the ladder slips down a distance of x, the foot of the ladder moves out x. find the distance of x.

a^2 + b^2 = c^2
a^2 + 5^2 = 13^2 ==> 169-25=144=a^2
therefore a = 12
after adjustment;
(12-x)^2 +(5+x)^2 = 13^2
144 - 24x +x^2 + 25 + 10x +x^2 = 169
2x^2-14x=0
x(2x-14)=0
x = 7 or 0
Therefore the distance moved is 7m.

thanks!

but shouldn't it be 0 or -7?

oh, sorry, i get it

Answer this Question

First Name:
School Subject:
Answer:

Related Questions

Mathematics - A Ladder AB, of length 13m, rests against a vertical wall with its...
Physics - A ladder of mass M and length 2 m rests against a frictionless wall at...
Physics - An 8.5 m ladder whose weight is 310 N is placed against a smooth ...
math - A ladder 10 m long rests on horizontal ground and leans against a ...
Geometry - A ladder 12 m in length rests against a wall. The foot of the ladder ...
Calculus - a 5m ladder rests against a vertical wall. The top of the ladder ...
Physics - A uniform ladder of length (L) and weight 100 N rests against a smooth...
math - A uniform ladder of length 2a and mass m lies on a vertical plane with ...
Calculus - related rates: a ladder, 12 feet long, is leaning against a wall. if ...
algebra - A ladder is resting against a wall. The top of the ladder touches the ...

Search
Members