Ask Your Question
0

Define the polynomial ring $\Bbb Q[c][x]$.Find the $c$ values where $x^2 + x + c + 1$ has a double root.

asked 2019-07-25 15:00:01 +0200

anonymous user

Anonymous

updated 2019-07-29 15:04:22 +0200

FrédéricC gravatar image

Sage question: Define the polynomial ring $\Bbb Q[c][x]$.Find the $c$ values where $x^2 + x + c + 1$ has a double root. Sage code I have found.

K.<c>=QQ['c']

R.<x>=K[]

f=x^2+x+c+1

f

How do I find the code for the $c$ values where $x^2 + x + c + 1$ has a double root. Also, can you give some examples so that I can construct some programming code in sage?

edit retag flag offensive close merge delete

Comments

Is it homework ?

tmonteil gravatar imagetmonteil ( 2019-07-28 21:14:54 +0200 )edit

1 Answer

Sort by » oldest newest most voted
1

answered 2019-07-29 14:58:39 +0200

rburing gravatar image

A polynomial has a double root iff its discriminant is zero, so:

sage: f.discriminant()
-4*c - 3
sage: f.discriminant().roots(multiplicities=False)
[-3/4]
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

1 follower

Stats

Asked: 2019-07-25 15:00:01 +0200

Seen: 1,039 times

Last updated: Jul 29 '19