We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive pseudonymised information about your use of our website. cookie policy and privacy policy.
 
+0  
 
0
101
1
avatar

Why is it when it says Sin(A) he puts theta which is the c angle? and when it says Sin(B) the A angle is put? is there something im missing 

 Oct 21, 2018
 #1
avatar+100595 
+1

Remember  that  cos (120)   =   -cos (60)   =  -1/2

 

So....using the Law of  Cosines

 

BC^2  =  x^2  + (3x)^2  -  2 (x) (3x) (-1/2)

 

BC^2   =  x^2  + 9x^2  + 3x^2

 

BC^2  =  13x^2

 

BC  = x sqrt (13)

 

So.....using the Law of Sines

 

Sin (BCA)  /  x  =  sin (120) / [ x sqrt (13) ]

 

Sin (BCA)  = sqrt (3)  / [ 2sqrt (13) ] =

 

Sin (BCA)  =  sqrt (39) / [ 2 * 13 ]  =   sqrt (39) / 26

 

 

cool cool cool

 Oct 21, 2018

28 Online Users

avatar
avatar
avatar