A community for students.
Here's the question you clicked on:
 0 viewing
anonymous
 5 years ago
question is, When is the particle moving forward (in the positive direction)?
equation: v(t)= 3t^212t+9>0
answer = positive direction when t<1 and t>3
negative direction when 1<t<3
i cant understand how the math book gets those answers!!! please help (its a rate of change question)
anonymous
 5 years ago
question is, When is the particle moving forward (in the positive direction)? equation: v(t)= 3t^212t+9>0 answer = positive direction when t<1 and t>3 negative direction when 1<t<3 i cant understand how the math book gets those answers!!! please help (its a rate of change question)

This Question is Closed

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Factor that polynomial you got there, to =3(t1)(t3) then you find that when t<1 and when t>3, your equation is positive. this function is stating that when v(t) is postive, the particle is moving in the "positive" direction and when the function is negative, it's moving in the "negative" direction.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0factor out the 3 from the polynomial, then factor it like any other polynomial. Or use the AC method if you're comfortable with it.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0maybe im factoring wrong, but can someone go through the factoring for me?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0v(t) = 3t^2  12t + 9 v(t) = 3 * (t^2  4t + 3) v(t) = 3 * (t  1)(t  3)

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0i got to that, but then wouldnt it be t>1 and t>3 ?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0It's when the quantities (t1) and (t3) are both either negative or positive. Because then you have 3 * a positive scalar quantity. So when t > 3, both (t1) and (t3) will be positive. When t < 1 both will be negative. It can't be when t>1 and t>3, because that would be the same as saying t>1. You only have one t, it can't be two things at once. Plus, think about when t=2. (t2) is positive but (t3) is negative. It will be traveling in the negative direction. Hope that helps clear things up a bit. :)

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0oh alright, i got it!! thanks soo much!
Ask your own question
Sign UpFind more explanations on OpenStudy
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.