Got Homework?
Connect with other students for help. It's a free community.
Here's the question you clicked on:
 0 viewing
Let f(x) = (x^2 + 3x – 4) and g(x) = (x + 4).
a. Find f • g and state the domain.
b. Find f/g and state the domain.
 one year ago
 one year ago
Let f(x) = (x^2 + 3x – 4) and g(x) = (x + 4). a. Find f • g and state the domain. b. Find f/g and state the domain.
 one year ago
 one year ago

This Question is Closed

kirk.freedmanBest ResponseYou've already chosen the best response.1
So I know I start by multiplying (x^2+3x4)(x+4)... I get x^3+7x^2+8x16 what now?
 one year ago

sparik1997Best ResponseYou've already chosen the best response.1
f • g=x^3+4x^2+3x^2+12x4x16=x^3+7x^2+8x16 the domain means what values can x get, here, x can be any real number. so the domain is all numbers.
 one year ago

kirk.freedmanBest ResponseYou've already chosen the best response.1
How do I know it is all numbers and there isn't like one number that doesn't work? Is there a way to check that?
 one year ago

sparik1997Best ResponseYou've already chosen the best response.1
f/g=(x^2 + 3x – 4)/(x+4) as we know, the denominator can't be equal to 0, so x+4 can't be equal to 0, that means, x can be any number but 4
 one year ago

sparik1997Best ResponseYou've already chosen the best response.1
if there is a square root or a denominator, you must consider that denominator can't be 0 and the expression in the square root is >=0
 one year ago

kirk.freedmanBest ResponseYou've already chosen the best response.1
Wait so what is f/g?
 one year ago

sparik1997Best ResponseYou've already chosen the best response.1
the domain of f/g is any real number but 4
 one year ago

kirk.freedmanBest ResponseYou've already chosen the best response.1
Yeah, that's the domain, but it says find f/g and then it says also find the domain, I thought that that means I need two answers there?
 one year ago

sparik1997Best ResponseYou've already chosen the best response.1
f/g=(x^2 + 3x – 4)/(x+4)
 one year ago

kirk.freedmanBest ResponseYou've already chosen the best response.1
wait, what would be the steps to find that the domain of f/g is all but 4?
 one year ago

kirk.freedmanBest ResponseYou've already chosen the best response.1
is it like x+4>=0 then subtract 4 from both sides so you have x>=4?
 one year ago

kirk.freedmanBest ResponseYou've already chosen the best response.1
dw:1356492631732:dw now what @Hero
 one year ago

kirk.freedmanBest ResponseYou've already chosen the best response.1
Oh yeah, I knew that xD thanks! so it's x1?
 one year ago

kirk.freedmanBest ResponseYou've already chosen the best response.1
And i'm done now?
 one year ago

kirk.freedmanBest ResponseYou've already chosen the best response.1
Thanks to both of you!
 one year ago
See more questions >>>
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.