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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..

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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
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