The answer is never, that is, on a 2 dimensional plane. You can perform an experiment to see why it is the case. On curved surfaces though, two lines can intersect one another more than once. For instance, on the surface of planet Earth, two lines can intersect one another, both at the Earth's North Pole and South Pole.
Answer:

✑ Question :
- Is ( 11 , 9 ) , ( 11 , 5 ) , ( 9 , 3 ) a function ?
No , it's not a function.
✎ Reason :
This is not a function because one element 11 of set A is associated to elements 9 and 5 of set B.
♨ Explore about function :
↪ Function is a special type of relation. It is the refinement of relation. In a relation from A to B , every element of set A should have only one ( distinct ) image in B to be a function. In other words , if no two different ordered pairs have the same first component , then it is a function.
Hope I helped!
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I hope this helps, If there are 5 cups of flour, then there will be 7 and 1/2 cups of sugar:)
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I'm not 100% sure on this answer, but I don't think anyone else will be answering.