if alphabeta are the zeros of the polynomial

Question

If  α,β are the zeros of the polynomial 2x² - 4x + 5 find the value of a) α² + β²  b) (α - β)².

Ans: p (x) = 2 x² - 4 x + 5           (Ans: a) -1 , b) -6)

α + β = -b /a = 4/2 = 2

α β = c/a = 5/2

α² + β² = (α + β)² - 2 α β

Substitute then we get, α ²+ β² = -1

(α - β)² = (α + β)²  - 4 α β

Substitute, we get  = (α - β)²  = - 6