Argumentative, which derives from argumentation, is the standard form of the adjective meaning (1) quarrelsome or given to argument, or (2) concerned with or relating to argumentation. The shorter argumentive appears occasionally, but it has never been an accepted form.
The man became argumentative and refused to get out of the roadway and return to his home. [Bay Net]
Others embraced the new pamphlet format to weigh in on the merits of Luther’s arguments, both for and against, like argumentative bloggers. [The Economist]
In one, an argumentative Israeli bargains in an American department to the evident confusion of the clerk who is unused to Middle Eastern haggling. [Globe and Mail]
For a liberal arts college, expository and argumentative writing should be as important as physical fitness. [The Dartmouth]
Obstreperous and argumentative for the sake of it, she found herself presented to the matriarch. [The Age]