When you have a graph, how can you tell when the domain or range is the set of all real numbers?

I tend to struggle with this and I would really like to know how I can tell. If anyone knows any website or video that breaks it down, it would mean a lot.

Question

When you have a graph, how can you tell when the domain or range is the set of all real numbers?

I tend to struggle with this and I would really like to know how I can tell. If anyone knows any website or video that breaks it down, it would mean a lot.

anonymous · Answer

https://www.khanacademy.org/math/trigonometry/functions_and_graphs/domain_range/e/range_of_a_function Go here to practice, there's videos and tutorials with hints. Hope it helps. Do plenty of examples and you'll get the hang of it. Draw the graph using a calculator to see why the domain and range of a function is a certain way.

amistre64 · Answer

if the end behaviours go in opposite direcetions .... itll cover all up and downs

anonymous · Answer

Thank you! This has been something that has been tough for me ever since I've learned about graphs. I understand most of the things about them, but that's one thing I've had a hard time with.