@CPhill

Look at the image, here :

The rope hangs from the point (0,4)..the bottom of the rope is at (0,1).....it swings out at a 60 degree angle (pi/3) from a vertical position in each direction....so....it reaches a height of 2.5 m as shown

but how would you find that algebraically? 

We can use this to find the height :

[1  +  3*sin (30°) ] m   =  [1  + 3 (1/2)] m   = [ 1 + 3/2 ] m   =   [1 + 1.5 ] m   =   2.5 m

Hi Julius and all others,

When you ask a question please include the whole question. 

I assume this question refers to an earlier thread - you should have asked your question with another post on the initial thread and then if you wanted to draw attention to it you could have made a new post just giving the link and saying that you have asked for more discussion/help.