inverse function

[Heinsbergrelatz]

okay i have problem, and i want to know how to solve these kind of questions in general. i think i get it, but its alittle confusing.

so the problem goes like this, say f(x)=-2x^2+10x-150, find the domain of f such that its inverse exists. I get the Domain of f(x)=R range f inverse, but maybe someone could clarify the situation here for me.

 

Thank you

Edited July 29, 2011 by Heinsbergrelatz

[Fuzzwood]

Easy, what does the inverse of a function actually mean? And how does domain relate to range?

[mathematic]

okay i have problem, and i want to know how to solve these kind of questions in general. i think i get it, but its alittle confusing.

so the problem goes like this, say f(x)=-2x^2+10x-150, find the domain of f such that its inverse exists. I get the Domain of f(x)=R range f inverse, but maybe someone could clarify the situation here for me.

 

Thank you

The point of the question is that there is more than one x for each value of f(x) (with one exception). Therefore to define the inverse properly, you have to breakup the x domain into pieces, so that there is only one x for each value of f(x).

[Heinsbergrelatz]

just to clarify for my example, is the domain [2.5.infinity] ??

[mathematic]

just to clarify for my example, is the domain [2.5.infinity] ??

Yes. Also (-infinity,2.5), but not both at the same time.

Edited July 31, 2011 by mathematic