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ImRebecca · 2013-11-08 18:40:56

How could I do this question? A cubic function f is defined for x e R as F(x) x^3+(1-k^2)x+k, where k is a constant Show that -k is a root of f. Any help would be appreciated thanks.

08-11-2013 6:40pm

#1

ImRebecca

Registered Users, Registered Users 2 Posts: 155 ✭✭

Join Date: December 2009

Posts: 127

How could I do this question?

A cubic function f is defined for x e R as
F(x) x^3+(1-k^2)x+k, where k is a constant

Show that -k is a root of f.

Any help would be appreciated thanks.

0

Comments

#2 08-11-2013 6:50pm

JackieChan

Closed Accounts Posts: 1,829 ✭✭✭

Join Date: May 2004

Posts: 1634

I dont want to just tell you straight out but think about what it means for the value of the function for when you have an X thats a root. That should make it obvious how you can show whether k is a root.

0