#TI-Basic, 11 bytes
TI-Basic, 11 bytes
Input should be in the form of a list, like {A B C}.
prod(Ans)/prod(sum(Ans)-2Ans Maybe this visual will help (remember that 2s = a+b+c):
abc abc abc prod(Ans) ---------------- = --------------------- = ------------------- = ------------------- 8(s-a)(s-b)(s-c) (2s-2a)(2s-2b)(2s-2c) (a+b+c)(1-2{a,b,c}) prod(sum(Ans)-2Ans)