A community for students.
Here's the question you clicked on:
 0 viewing
no.identity05
 one year ago
how to derive cosine law from sine law? can anybody help me.. please..
no.identity05
 one year ago
how to derive cosine law from sine law? can anybody help me.. please..

This Question is Open

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0the law of sines tells us that for a triangle with sides \(a,b,c\) and opposite angles \(A,B,C\) we have $$\frac{\sin A}{a}=\frac{\sin B}{b}=\frac{\sin C}c=K$$ for some constant \(K\)

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0now consider \(A+B+C=\pi\) so expand: $$\sin(\piBC)=\dots\\\sin(\piAC)=\dots\\\sin(\piAB)$$

no.identity05
 one year ago
Best ResponseYou've already chosen the best response.0i really don't get your point, can you show me how? this formulas must be use (a/sinA)=(b/sinB)=(c/sinC)=2R where R is raduis of circumcircle and area of triangle=(1/2)(ab)sinC

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0https://en.wikipedia.org/wiki/Law_of_cosines Read the part "using law of sin", it is exactly what @oldrin.bataku wrote
Ask your own question
Sign UpFind more explanations on OpenStudy
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.