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seen Jul 31 '12 at 16:59

Sep
11
awarded  Notable Question
May
13
awarded  Popular Question
Aug
1
comment Prove $\sin^2(A)+\sin^2(B)-\sin^2(C)=2\sin(A)\sin(B) \cos(C)$ if $A+B+C=180$ degrees
Fernando Martinez appreciates all the post and the work that went into answering his question.
Jul
31
comment Prove $\sin^2(A)+\sin^2(B)-\sin^2(C)=2\sin(A)\sin(B) \cos(C)$ if $A+B+C=180$ degrees
What would I do next I am not sure what to do.....
Jul
31
comment Prove $\sin^2(A)+\sin^2(B)-\sin^2(C)=2\sin(A)\sin(B) \cos(C)$ if $A+B+C=180$ degrees
I see my now so technically would I have now sin^2B-sin^2C=cos(a-b+c)-cos(a+b-c)=cos2c-cos2b=2sin^2B-2sin^2C
Jul
31
awarded  Student
Jul
31
comment Prove $\sin^2(A)+\sin^2(B)-\sin^2(C)=2\sin(A)\sin(B) \cos(C)$ if $A+B+C=180$ degrees
Hmm which two would I cancel out.
Jul
31
comment Prove $\sin^2(A)+\sin^2(B)-\sin^2(C)=2\sin(A)\sin(B) \cos(C)$ if $A+B+C=180$ degrees
Sasha would I start on the right or left side sorry if its a dumb question....
Jul
31
comment Prove $\sin^2(A)+\sin^2(B)-\sin^2(C)=2\sin(A)\sin(B) \cos(C)$ if $A+B+C=180$ degrees
thanks for your post I will study them and use them to solve the problem.
Jul
31
asked Prove $\sin^2(A)+\sin^2(B)-\sin^2(C)=2\sin(A)\sin(B) \cos(C)$ if $A+B+C=180$ degrees