Question

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Answer 1

helo???

Answer 2

Hey I am here

Answer 3

Am I VIP?

Answer 4

prove that IF A+B+C=180, sin^(A/2)+sin^2(B/2)-sin^2(C/2)=1-2cos(A/2)cos(B/2)sin(C/2)

Answer 5

INDEED

Answer 6

hmm Okay I will have to try this

Answer 7

.............

Answer 8

YES

Answer 9

well sin^2(a/2)=1/2-1/2cos(2(a/2))=1/2-1/2cos(a)
sin^2(b/2)=1/2-1/2cos(b) similar as above
-sin^2(c/2)=-1/2+1/2cos(c) similar as above
EQ=1/2-1/2cos(a)-1/2cos(b)+1/2cos(c)

Answer 10

wow if a+b+c=180 prove that cos a+cos b+cos c=1+4sin(a/2)sin(b/2)sin(c/2)

Answer 11

i dont know this one, sorry :( ill think about it, if no one else tackles it, ill try again