Rafael Bombelli died in 1572.
Rafael Tufiño died in 2008.
Rafael Guastavino died in 1908.
Rafael Garzón died in 1923.
Rafael Coello Ramos died in 1967.
Rafael Guerra Bejarano died in 1941.
Rafael Bombelli has written: 'L' algebra' -- subject(s): Early works to 1800, Algebra
Sebastiano Bombelli died in 1719.
Sebastiano Bombelli was born in 1635.
Rafael Bombelli is usually credited with discovering imaginary numbers in 1572. There were hints of the theory going back much further, perhaps beginning with Hero of Alexandria in the first century.
The Italian mathematician, Gerolamo Cardano was the first to consider the concept of complex numbers. However, he did not develop a theory of complex numbers to any extent. That was left to Rafael Bombelli.
+i and -i
rapael bombelli
It looks like it was most likely Rafael Bombelli in 1572, from what I can find. I've posted a related link to a Wikipedia article. Wikipedia should not be your sole source of information, but it's a starting point.
Gideon Rafael died in 1999.
Rafael Corpus died in 1960.
Rafael Godoy died in 1973.
Rafael Carmoega died in 1968.