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VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Mathematical Methods CAS => Topic started by: tolga on December 23, 2009, 11:56:09 pm

Title: polynomials help
Post by: tolga on December 23, 2009, 11:56:09 pm: 2)The functions y=x^3-2x^2+ax+10 and y=6+(a+b)x-4x^2-x^3 both have (-1,0) as an x-intercept. Find the values of a and b>
Title: Re: polynomials help
Post by: /0 on December 24, 2009, 01:08:50 pm: Just plug in the coordinates:

$y=x^3-2x^2+ax+10$

$0 = (-1)^3-2(-1)^2+a(-1)+10$

Solve for a.

Then:

$y=6+(a+b)x-4x^2-x^3$

$0=6+(a+b)(-1)-4(-1)^2-(-1)^3$

Solve for b.