Carlos G.

asked • 12/09/14

Law of Cosines

Use the Law of Cosines to find angle B if a=4,b=6, and c=9 (Round to 2 decimals places)
I don't know if this answer is right but this is what I did
cos B = (6^2 - 4^2 - 9^2/-2(4)(9)) = ((36-15-81)/-72) = -61/-72 = .8472222222
Then I used my calculator 
Answer : 
cos B = 32.09
Don't know if this is the right answer

2 Answers By Expert Tutors


Bryce S. answered • 12/09/14

5.0 (181)

Experienced, Patient, Empathic Tutor for Math, Writing

Carlos G.

Yeah I miss type 15 I mean't to type 16 not 15 


Bryce S.

I figured you did, I only pointed on the chance that you hadn't noticed it. Btw, if you think my answer is the best, please consider marking it as the best.
Thank you,


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