Verify that 1, -1 and -3 are the zeroes of the cubic polynomial x³+3x²-x-3 and check the relationship between zeroes and the coefficients.
Answers
Step-by-step explanation:
let p (x) = x^3 + 3x^2-x-3
x = 1 = P(1) = 1^3+3×1^2-1-3
= 1+3-1-3=4-4=0
X = -1 = P(-1) = (-1)^3 + 3×(-1)^2-(-1)-3
= -1+3+1-3=4-4=0
X = -3 = P(13) = (-3)^3+3(-3)^2-(-3)-3
= -27+27+3-3=0
since, 1,-1 & -3 are the zeroes of the given
cubic polynomial
let, a = alfa and b = beta,
a = 1 , b = -1, r = -3
zeroes. coefficents
a= 1. A= 1
b=-1. B=3
r=-3. C=-1
D=-3
a+b+r= -B/A = 1+(-1)+(-3) = -3/1
= 1-1-3=-3= -3 = -3
ab + br + ar = C/A
= 1(-1)+(-1)(-3)+(1)(-3) = -1/1
= -1+3-3 = -1 = -1
abr = -B/A = 1(-1)(-3) = -(-3)/1 = 3
= 3