if alpha and beta are the zeroes of a quadratic polynomial 2x^2 - 3x - 5 form a polynomial whose zeroes are (i)alpha^2 and beta^2 (ii)1/alpha^2 and 1/beta^2
The polynomial can be factored into: (x+1)(2x-5), so we have α = -1 and β = 5/2
(i) The polynomial with zeros α2 and β2 can be factored as (x - α2)(x - β2). This can be multiplied out to get
x2 - (α2 + β2)x + α2β2 or x2 - (1 + 25/4)x + 25/4 or x2 - (29/4)x + 25/4
Multiply all the terms by 4 to get 4x2 - 29x + 25
See if you can now do part (ii).
The polynomial can be factored into: (x+1)(2x-5), so we have α = -1 and β = 5/2
(i) The polynomial with zeros α2 and β2 can be factored as (x - α2)(x - β2). This can be multiplied out to get
x2 - (α2 + β2)x + α2β2 or x2 - (1 + 25/4)x + 25/4 or x2 - (29/4)x + 25/4
Multiply all the terms by 4 to get 4x2 - 29x + 25
See if you can now do part (ii).
If alpha and beta are the zeroes of a quadratic polynomial 2x2−3x−5 form a polynomial whose zeroes are
The roots for this is 2.5 an -1 These are αandβ
(i) α2=6.25andβ2=1
In any quadratic ax^2+bx+c the sum of the roots is given by -b/a = 7.25
and the product of the roots is c/a = 6.25
So one solution would be x2−7.25x+6.25
(ii) 1α2and1β2
Rootsare16.25=425=0.16and1so−ba=1.16andca=0.16Leta=1$Soonesolutionwouldbe$x2−1.16x+0.16