Pre calc help!

Question

Pre calc help!

math_man21 · Answer

hit me

anonymous · Answer

Domain of f
3x(power of 2) +1
(I hate my tablet :/)

math_man21 · Answer

idk jk

hartnn · Answer

you mean you want the domain of 
$f(x) = 3x^2 + 1$
??

well, what values does x cannot take?

anonymous · Answer

Yep
Wdym?

hartnn · Answer

ok,

if we have a $\sqrt..$, then the function inside that square root must be positive.
the values of x that make the $\sqrt. $ negative are not in the domain.

similarly,
the denominator of a function cannot be = 0.
the values of x for which the denominator = 0 are not in the domain.

so for 3x^2+ 1
what are the values of x which are not in the domain of x?

anonymous · Answer

Wait, to find a domain, you would need to havea graph right?

hartnn · Answer

you can, thats one way.
what we are doing is trying to find it algebraiclally.

anonymous · Answer

Well then i have no clue cause i only learned by graph.

hartnn · Answer

so if you plot 3x^2 +1,
what do you observe ?

hartnn · Answer

is there any value that x cannot take?

anonymous · Answer

Um, give me a min

anonymous · Answer

It can take any value...

hartnn · Answer

right!

so the domain is all real numbers :)

anonymous · Answer

Oh ok. Thanks! :D

hartnn · Answer

welcome ^_^