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- Proof of triangle inequality 9 answers
Prove that each of the group R :
$$|x+y| \leq\ |x| + |y|$$
Of course I'm not a lazy person I tried solving before since the teacher gave this exercise to us in the exam. I wanted to know the right answer because we still haven't corrected the test.
Thanks and Sorry for any faults. This is my first question in this website. How would I know if it's duplicate?