PARALLELOGRAM OF PuBCU, 



; nuns than one tAJtttiflTi ; for cianv 



it* < (.r) - 2 co* rx, or if < r -^^-a"", where 



i is satisfied; we hall however shew 

 admUaihlc in the present qtettioft M 



t(*)-teo**., 



may observe that we need not consider any value of m 

 greater than , for the direction* of two forces acting at a 



always m angle leas than v; wo may then 



assume it as obvious that (x) must be a positive quaui 



shall first shew that if (x) - t oos x when x has any 

 value a, then ^(x) must -2 coax when xhaa the value ? 



it x and i each equal to J, so that *)(*+*) 

 equal to 2 cos a ; ' 



! rrsuhaiit of two equal forces acting in th- lam* 



tho COJlpOsjfBt forces; 

 ,>(0)-2: re by (3) 



ace *(*)-3co^ butbytapposition julcaithan 

 j , and </>Q) must be a /wti'lire quantity ; thus 



*- 



-! 



^(x)-coswhent5-| f then >()- cot* 

 i-?;andsoon. Thiu we conclude that if X*)-*eoa* 



