Find all the zeros of (2x4 ‒ 3x3 ‒ 5x2 + 9x ‒ 3), it being given that two of its zeros are √3 and – √3.
Let us assume f (x) = 2x4 - 3x3 ‒ 5x2 + 9x - 3
As and – are the zeros of the given polynomial therefore each one of (x - ) and (x + ) is a factor of f (x)
Consequently, (x – ) (x + ) = (x2 – 3) is a factor of f (x)
Now, on dividing f (x) by (x2 – 3) we get:
f (x) = 0
2x2 - 3x2 – 5x2 + 9x - 3 = 0
(x2 – 3) (2x2 – 3x + 1) = 0
(x2 - 3) (2x2 – 2x – x + 1) (2x – 1) (x - 1) = 0
(x – ) (x + ) (2x – 1) (x - 1) = 0
∴ x = or x = - or x = or x = 1
Hence, all the zeros of the given polynomial are , -, and 1