Question

√5 and -√5 are two zeros of the polynomial x³+3x²-5x-15 then third zero is

Answer 1

Answer:

given polynomial

p(x) = x³ +3x² -5x -15

on comparison with the standard form of a cubic polynomial

We get,

a = 1

b= 3

c = -5

d = -15

given that two roots are √5 and -√5et the third root be ß

now

sum of roots = -b/a

= > √5 -√5 + ß = -3/1

=> ß = -3

so, the roots are √5, -√5 and ß.