+0  
 
+1
28
1
avatar+333 

https://vle.mathswatch.co.uk/images/questions/question15442.png

lynx7  Feb 11, 2018
Sort: 

1+0 Answers

 #1
avatar+82944 
+2

a. cos (60)  =   1/2

 

b. Using the Law of Cosines

 

b^2  =  8^2  + 5^2  -   2 (8) (5) cos (1/2)

 

b^2  =  64 + 25  - 80 (1/2)

 

b^2   =  89  -  40

 

b ^2  =  49       take the positive root

 

b  = 7

 

 

cool cool cool

CPhill  Feb 11, 2018

8 Online Users

avatar
We use cookies to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners.  See details