Why do you need to know absolute value?

Answer 1

You need to know what abs() means, because you need to apply the mathematical operation sometimes.

a) sometimes, you don't care about the sign, because you know, 100% sure, that the answer has to be positive (such as a person's height or age). Dealing with all positive numbers make calculations faster and writing clearer.

b) You need to plot the values of a quantity in logarithmic scale, and the quantity acquires a negative sign because of the measurement technique or the instrument's readouts. Computers cannot calculate the logarithm or square root of a negative number.

c) You don't want the program to bomb/abort when the square root or logarithm of a negative number during program executions.

d) The instrument is measuring a very small number and sometime the readout can turn negative but meaningless. Take the absolute value eliminates headaches of fautly arithmetic operations later.

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