Got Homework?
Connect with other students for help. It's a free community.
Here's the question you clicked on:
 0 viewing

This Question is Closed

ParthKohli Group TitleBest ResponseYou've already chosen the best response.0
\[x(x + 2) \ge 0\]
 one year ago

ParthKohli Group TitleBest ResponseYou've already chosen the best response.0
Observe that if you want \(x \times (x + 2)\) nonnegative, both \(x\) and \(x + 2\) are nonnegative.
 one year ago

Christos Group TitleBest ResponseYou've already chosen the best response.0
First time I am solving a 2nd degree inequality :S
 one year ago

Christos Group TitleBest ResponseYou've already chosen the best response.0
Could someone help me continue? :)
 one year ago

DrKingSchultz Group TitleBest ResponseYou've already chosen the best response.0
I can offer an alternative. Just sketch the graph. That never fails.
 one year ago

Christos Group TitleBest ResponseYou've already chosen the best response.0
I need to do it without a graph
 one year ago

nitz Group TitleBest ResponseYou've already chosen the best response.0
\[x \le 2 \] and \[x \ge0\]
 one year ago

Christos Group TitleBest ResponseYou've already chosen the best response.0
How and why?
 one year ago

DrKingSchultz Group TitleBest ResponseYou've already chosen the best response.0
Okay, then first find the xaxis intercepts by treating the inequality sign as an equals sign. \[x ^{2}+2x=0\] \[x(x+2)=0\] \[x=2,0\] Sub in values for \[x<2\] e.g when x=3, y=3 Then sub in values for x>0 e.g when x=1, y=3 Since \[x \in (\infty,2)\]and \[x \in (0,\infty)\]yield positive answers Therefore \[x ^{2}+2x>=0\] for x=<2 and x>=0
 one year ago

Mertsj Group TitleBest ResponseYou've already chosen the best response.0
Two factors: x and x+2 If the product is positive, x and x+2 must both be positive OR x and x+2 must both be negative. Let us make a picture of the factors and their signs at various points on the number line:
 one year ago

Mertsj Group TitleBest ResponseYou've already chosen the best response.0
dw:1362224143800:dw
 one year ago

Mertsj Group TitleBest ResponseYou've already chosen the best response.0
And so we see that the product is positive if x <2 OR x>0 and that is the solution.
 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.