Ask Your Question
1

Missing root when solving equation in sageMath

asked 2018-07-18 01:58:17 +0100

Sam Tan gravatar image

updated 2018-07-18 02:28:53 +0100

tmonteil gravatar image

When I solve equation using sageMath, it missed one root.

sage: solve([4/5*(x - 1)^2/x^(1/5) + 2*(x - 1)*x^(4/5)==0] ,x)

[x == (2/7), x == 1]

The equation has 3 roots. It misses x==0.

What is the reason?

edit retag flag offensive close merge delete

1 Answer

Sort by ยป oldest newest most voted
1

answered 2018-07-18 02:29:59 +0100

tmonteil gravatar image

updated 2018-07-18 02:32:03 +0100

Because of the denominator x^(1/5), the function you are considering is not defined at $x=0$. You can have a look at its plot to get convinced:

sage: f = 4/5*(x - 1)^2/x^(1/5) + 2*(x - 1)*x^(4/5)
sage: f.plot(0,1)
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: 2018-07-18 01:58:17 +0100

Seen: 257 times

Last updated: Jul 18 '18