soty2013 2 years ago How to find Domain and range of any given function ?

1. math>philosophy

You have to find when the function is undefined or doesn't produce real numbers to find the domain. The range is a bit trickier, but another method is to use the graph of the function

2. soty2013

3. soty2013

i am totally confused by reading multiple books, and finally i am totally confused. Plz help

4. karatechopper

(x,y) x=domain y=range

5. soty2013

@nincompoop

6. soty2013

@math>philosophy

7. soty2013

@math>philosophy

8. soty2013

@math>philosophy

9. soty2013

plz plz plz

10. karatechopper

I don't think he is gonna come..

11. soty2013

i beg for HELP

12. soty2013

PLZ PLZ PLZ HELP

13. zzr0ck3r

to find the domain , you need to find what cant be an input and exclude that from the real numbers, to find the range take the inverse of the function and do the same thing to the inverse

14. satellite73

it is really a lot easier to answer a question like this with a specific example. it depends almost entirely on the given function

15. satellite73

for example, if you have a trigonometric function like $$\sin(x)$$ whose domain is all real numbers and whose range is $$[-1,1]$$ you have to know something about the function to start even more so with a function like $$\arcsin(x)$$ whose domain is $$[-1,1]$$ and whose range is $$[-\frac{\pi}{2},\frac{\pi}{2}]$$

16. zzr0ck3r

correct, the way I explained was a general way that assumed the function was 1 to 1

17. satellite73

so there is not one mathematical method "find the domain" or "find the range" the real truth is that the domain is supposed to be part of the definition of the function to begin with, so the question "find the domain" is in fact inaccurate

18. satellite73

it would be much more enlightening to ask "find the domain and range of $$f(x)=\frac{x-1}{x+1}$$ or something more specific

19. soty2013

is it applicable to each type of functions ?

20. soty2013

?