We can't use both. The answer is to use the one with the smaller absolute value: With this definition of. A slightly different formal definition of the limit is used when x goes to +/- infinity, since we really cannot subtract x from infinity or vice versa-remember, infinity is a concept, not a number. Formally, the expression. Means that.
During the long interval of the Precambrian Era (which includes approximately 90% of geologic time and includes three Eons: the Hadean, the Archean and the Proterozoic) the only inhabitants of the Earth were simple microscopic organisms, many of them comparable in size and complexity to modern-day bacteria.
Their body is made up of just one single cell. E.g. - Amoeba, Paramecium. The oldest forms of life are the unicellular organisms and they existed 3.8 billion years ago. Bacteria, Amoeba, protozia, viruses, diatoms are the five different types of unicellular organisms.This single cell regulates the various functions of the body.Unicellular organisms are invisible to the naked eye.Unicellular organisms vary in size.acteria, Amoeba, protozia, viruses, diatoms are the five different types of unicellular organisms. This single cell regulates the various functions of the body. Unicellular organisms are invisible to the naked eye. Unicellular organisms vary in size.