FUNCTION

[Mikey]

HELLO, I AM NEW. I'M WORKING ON THIS PROBLEM

Give the domain of the function

f(x) = 2x^2 + 9x - 3

SO OK I KNOW MY CHOICES ARE ∞ AND 0 BUT I DON TKNOW IF THEY ARE NEGATIVE OR POSTIVE. MY FRIEND TOLD ME HE GOT (-∞, 0) FOR HIS ANSWER, BUT I DONT KNOW IF I SHOULD BELIEVE HIM, SO I CAME ON HERE TO GET SOME HELP AND FEEDBACK.

THANKS,

MIKEY

 

[Unco]

Polynomials always have a domain of \(\displaystyle \mbox{(-\infty, +\infty)}\); but anyway, can you sketch a parabola (any will do)? Can you infer the domain from that?

 

[thetomps]

Welcome Mikey,

I can try to help, but I am on here for help as well. When I did it I got (0, ∞)

 

[Unco]

Plug in a negative number for x.

 

[megynbrown1]

Hello Mikey,

I am getting (-∞, ∞)

 

[stapel]

When I did it I got (0, ∞)

When you "did" what? You got "it" how?

Please stop posting incorrect answers to other students' posts. Thank you.

Eliz.

P.S. to the original poster: Please review the reply posted by Unco, as it contains very useful information for many questions of this sort.