How does one prove that -LSB- math -RSB- a ^ 3 + b ^ 3 + c ^ 3 = 3abc -LSB- / math -RSB- ?
How does one prove for -LSB- math -RSB- a , b , c \ ge 0 -LSB- / math -RSB- that -LSB- math -RSB- a ^ 3 + b ^ 3 + c ^ 3 \ ge 3abc -LSB- / math -RSB- ?