2x Maths Questions (1 Viewer)

[SpiralFlex]

I'll say this once again, I solved it in the complex field, those are the only solutions, there are no real solutions.

Most likely.

 

[ohexploitable]

Most likely.

Definitely.

 

[SpiralFlex]

Varin, can we have the answer from the book?

 

[AAEldar]

Definitely.

After seeing my lol error, agreed.

 

[Alkanes]

He probably just made it up :$

 

[SpiralFlex]

Now wasn't that a fun hour?

 

[SpiralFlex]

He probably just made it up :$

I know i've seen this question in the Cambridge book somewhere.

 

[Varin9]

回复: Re: 2x Maths Questions

Varin, can we have the answer from the book?

LOL it was for homework from my tutoring colleage, i dunno the answer, i cant do it

 

[SpiralFlex]

Re: 回复: Re: 2x Maths Questions

We are stumped too. Year 11 is in a couple of days.

 

[ohexploitable]

Re: 回复: Re: 2x Maths Questions

LOL it was for homework from my tutoring colleage, i dunno the answer, i cant do it

Tell your tutor this then lol:

or

 

[SpiralFlex]

Re: 回复: Re: 2x Maths Questions

Tell your tutor this then lol:

He/she will be amazed at your skills.

 

[khfreakau]

Re: 回复: Re: 2x Maths Questions

Yeah, consider this.
If p^2 + q^2 + r^2 = 3, then -1 =< p,q,r =< 1
Considering the third equation
p + 2q - r = 5
The maximum value of the LHS considering the above condition is 1 + 2 + 1 = 4 =/= 5, therefore no real solutions.

Of course, that's assuming each of them is like that, after rereading it, this assumption is wrong. Irrespective of that, I'm still going to try and find out why this equation is wrong.

Okay, my bad, the condition is actually
root3 < p,q,r < root3
but i don't see how that helps. Okay I cbf now =)

 

[jyu]

Re: 回复: Re: 2x Maths Questions

OK

Try
p^2 + q^2 + r^2 = 5
p + q + r =1
p + 2q - r = 5

 

[ohexploitable]

Re: 回复: Re: 2x Maths Questions

OK

Try
p^2 + q^2 + r^2 = 5
p + q + r =1
p + 2q - r = 5

p=0, q=2, r=-1

or

p=9/7, q=8/7, r=-10/7

 

[jyu]

Just solved it.



Or



Will post working up in a sec.

AAEldar had the answers first

 

[AAEldar]

Re: 回复: Re: 2x Maths Questions

p=0, q=2, r=-1

or

p=9/7, q=8/7, r=-10/7

That's what I had before hahaha.

 

[Drongoski]

Re: 回复: Re: 2x Maths Questions

Tell your tutor this then lol:

I have hand-checked your 1st set of values for p, q & r and they satisfy all 3 equations.

I believe the 2nd solution will also be confirmed

You, Sir, are obviously a genius.


Why don't you post your full solution.

 

[annagurl]

Re: 回复: Re: 2x Maths Questions

Tell your tutor this then lol:

Hey... not to be rude, but do you guys seriously do that sort of stuff in general maths?

 

[ohexploitable]

Re: 回复: Re: 2x Maths Questions

Why don't you post your full solution.

It's actually really simple!

1. Go to http://wolframalpha.com
2. Type in each equation, separated with commas.
3. Click on the "=" sign.
4. ????
5. PROFIT!!!

http://www.wolframalpha.com/input/?i=p^2+q^2+r^2=3,+p+q+r=1,+p+2q-r=5

However... it might not work as well in an exam

 

[Varin9]

回复: Re: 2x Maths Questions

yeah its right lol, i know seems wierd