Totally Radical!

The word "radical" comes from the Latin word "radix", meaning "root", from which we get not only the word "radical", but also "radish"! Other English words related to “radix” are rutabaga, race, and eradicate.The other use of "radical" means "by the roots" or "from the roots", that is, complete, such as a "radical" change in a person. Another word from the same source is "eradicate" (originally, to "root out" or "pull out by the roots"). The word radix was used for the branches or roots of plants. Later it was generalized to mean origin or beginning. The radical symbol first appeared in 1525 in Die Coss by Christoff Rudolff (1499-1545). Christoff Rudolff wrote Coss (1525), the first book of algebra to appear in German.

In arithmetic the root of a number is the number that is used to build up another number by repeated multiplication. Since 8 = 2*2*2 we say that 2 is the third root of eight. The word root is also used in the mathematics of functions to indicate the value that will produce a zero (a ground level number) for the function. If f(x)= x2-9 then x=3 is one of the roots or zeros of the function. The same root word also gave us the word radical which is used for the symbol indicating a root. Students often call this the square root sign.