Reciprocal 3 : If two numbers are so related that when multiplied together the product is 1, each is the reciprocal of the other. Thus the numbers 3 and 1/3 are reciprocals of each other since they equal 1 when multiplied together
H. J. Porter (Chairman - Technical Committee), Dictionary of Fire Technology, The Institution of Fire Engineers, The Victory Press (Leicester) Ltd. 1979 UK. (Fr Tech - Brit) {81}