If α, β are the roots of the equation x2 + 15x + 17 = 0, find (α−β)2.
128
147
157
138
(α−β)2 = (α+β)2 - 4αβ
α + β = -15 αβ = 17
⇒ (α−β)2 = 152 - 4 × 17
= 225 - 68
= 157
α, β are the roots of the equation x2 + 14x + 10 = 0. Find the value of (α2 + β2).