Trivial Q (1 Viewer)

OLDMAN

Member
Joined
Feb 20, 2003
Messages
251
Location
Mudgee
Gender
Undisclosed
HSC
N/A
If 4 distinct points of the curve y=4x^4+14x^3+6x-10 are collinear, then their mean x-coordinates is a constant k. Find k.

Trivial if you find the key!
 
N

ND

Guest
Let a and b in the line y=ax+b be such that the line cuts the curve y=4x^4+14x^3+6x-10 in 4 places.
Solving simultaneously:
4x^4+14x^3+(6-a)x-10-b=0
Now k = (sum of roots of this eq)/4
= -14/4 * 1/4
= -14/16

Hmmm is that right? Cos it seems that no matter what a and b are, the sum of the roots would be the same, which kinda defeats the purpose of saying "4 distinct points" in the question.
 

OLDMAN

Member
Joined
Feb 20, 2003
Messages
251
Location
Mudgee
Gender
Undisclosed
HSC
N/A
The sum is a constant but not the points.

Anyway, nice work.
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top