Question

which of √2 and 2 is a zero of polynomialp(x) =x3-2x? why? ​

Answer 1

Let's solve this by trial and error method,

if we put root 2 as x,we will get this :

root 2 ^3 - 2root2

or, 2root2 - 2root2 = 0

Hence, root 2 is a zero of given polynomial.

if we put 2 as x, we will get this :

2^3 - 2 x 2

or, 8 - 4 = 4 ,which is not equal to zero .

Therefore, 2 is not a zero of given polynomial.