how to know the which one equation is one to one function and many to one function? can anyone explain to me?

Question

mathmate · Answer

You have probably used the vertical line test to determine if a given relation is a function.  Use the similar "horizontal line test" to test a function to see if it is one-to-one.
If any horizontal line cuts the function at zero or one point, the function is one-to-one.
For example, y=2x is a one-to-one function, while $ y=x^2 $ is not .

anonymous · Answer

ok..i understand.. if many to one equation?

anonymous · Answer

this link will help you http://mathonweb.com/help_ebook/html/functions_6.htm