Can someone help me with my math homework? (1 Viewer)

[PatB]

I'm trying to help someone with this problem but I can't seem to break it, I'm not cheating or anything so it's all on the up and up.



12y^3-6y^2-42y+28=0

Solve for y.

(I don't know if this is the proper way to type this but for example the first part is 12 "y" cubed.)

 

[James~P]

factor it or use quadratic equation.

 

[PatB]

You can't use a quadratic equation to factor a cubic though.
I was trying to factor it but that's the problem, I can't seem to do it.

 

[James~P]

if i rememberd any of this from 8th grade i'd help more...

 

[PatB]

You may want to go back to spelling.

That's the problem, it's for an 12th grader.

 

[Bryan X]

-1.9338

 

[James~P]

my spelling is sub par late at night when i'm going fast.. that wasnt even what you'd consider spelling.. it was just a typo...



anyway if you have a palmpilot just download "math pad" and use it to solve the equation

 

[Dome Vongvises]

Give me a second, I'm working on this.

 

[PatB]

Hey Bryan, is that for real or are you just goofing?

Just a little humour James, math isn't my strong suit.

 

[Patrick Sun]

The other solution is pretty close to 1.74075.

 

[PatB]

What is 1.74075? Is that some kind of magic number?

 

[Bryan X]

Yep, PatB, that's for real.

 

[PatB]

Bryan, can I ask how you got to that result?

 

[Dome Vongvises]

Well, I've got it simplified down to 6y^3 - 3y^2 - 21y + 14 = 0. That's where I'm stuck.

I think you'll have to graph this one.

 

[Bryan X]

Well, I'd like to say that I solved it on paper, but it's been way too long since I've been in school/college.

http://school.discovery.com/homework...th/nsolve.html

 

[Tony-B]

Pat, make sure it's true by plugging in his answer for Y.

Sorry if I am stating the obvious, but I just want to make sure that you do that.

 

[PatB]

Awww, that's a shame, I need to see what the solution is. It's not about the destination, it's about the journey, in zen-speak.

 

[Bryan X]

It's not about the destination, it's about the journey

Until you get out of school and into work, then it's ALL about the destination....

 

[PatB]

I'm just trying to help out a friend here, now I'm getting lectured by Bryan.

 

[Bryan X]

It appears that there is more than one answer however. I've created the equation in Excel and found more than one answer-- depending on how many decimal places you are taking this out to consider zero.