
John M. answered 03/26/20
Math Teacher/Tutor/Engineer - Your Home, Library, MainStreet or Online
prove: a3sin(B-C)+b3sin(C-A)+c3sin(A-B)=0
If you make an isosceles 45:45:90 degree triangle
where a=c, Angle A = 45 = Angle C and Angle B = 90 degrees,
a^3Sin(90-45) + b^3Sin(45-45) + c^3Sin(-45)
where a = c
a^3Sin(45) + b^3Sin(0) + a^3Sin(-45) = a^3Sin(45) - a^3Sin(45) = 0