Question

Find the zeroes of the quadratic polynomial 8x^2-21-22x and verify the relationship between the zeroes and cofficients of the polynomial

Answer 1

p(x) = 8x2-22x-21

= 8x2-28x+6x-21

= (4x+3)(2x-7)

= then the zeroes are,

= 4x+3 = 0 , 2x-7 = 0

= x = -3/4 and x = 7/2

= relationship verification ,

= let α = -3/4 and β = 7/2

sum of zeroes = α+β
= -3/4+7/2
= 11/4

product of zeroes = αβ
= -3/4 . 7/2
= -21/8

relationship verification by coefficient

sum of zeroes = -b/a
=-(-22)/4
= 11/4

product of Zeroes = c/a
= -21/8

hence relationship is verified