T R I 



Solution 2d. Let a be greater than b. Find in the tables an /_ 9 such 



The latter method is the most concise in those cases in which the logs. 

 of a and b are given. 



Case 3d. 

 Given a, b, c to find A, B, C. 



Soli 

 Soli 



ution 1st. Let 8 = t+J-., the,, (.to. )' = ,< X S^L^L 

 ution2d. (Cos. ^y = < X R '^7"' ) . 



Scions, (Tan.f)' =HX^^.' 



If the ^ sought be less than SO use 1st method. 



If __ ____ __ . greater than 90 use 2d method. 



The third method may be used in all cases, except when the /_ sought 

 is nearly 18O>. When the ^ sought i# very small, and great accuracy 

 is required, a peculiar computation is necessary. 



