Ask Your Question
0

Need positive sqrts only

asked 2012-06-11 10:11:43 +0100

Mr Cool gravatar image

Hi,

I have solved some equations using solve() which does some manipution then takes a few positive and negative sqrts and then some more manipulation. There are several sets of solutions, but it's not obvious which ones correspond to which sign of sqrts. Is there an easy way I can make solve() only take positive square roots?

Thanks! And let me know if more info is needed.

edit retag flag offensive close merge delete

1 Answer

Sort by ยป oldest newest most voted
3

answered 2012-06-11 16:24:51 +0100

Shashank gravatar image

You can make sure solve returns only positive square roots by making sure that the argument of square root is positive. For eg.

solve(x*x==1,x)

gives x=1,x=-1

however,

assume(x>0)
solve(x*x==1,x)

returns x=1

I might be able to give a better answer if you could give me a simplified example of the problem.

edit flag offensive delete link more

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

Question Tools

Stats

Asked: 2012-06-11 10:11:43 +0100

Seen: 412 times

Last updated: Jun 11 '12