If one root of x² + px + q = 0 may be the square of the other, then p^3+q^2 +q= About the author Raelynn
Let root of the given equation x 2 +px+q=0 are α and α 2 Then, we have α⋅α 2 =α 3 =q and α+α 2 =−p On cubing both sides, we get α 3 +(α 2 ) 3 +3α.α 2 (α+α 2 )=−p 3 ⇒q+q 2 +3q(−p)=−p 3 ⇒p 3 +q 2 +q(1−3p)=0 Reply
Let root of the given equation x
2
+px+q=0 are α and α
2
Then, we have α⋅α
2
=α
3
=q and α+α
2
=−p
On cubing both sides, we get
α
3
+(α
2
)
3
+3α.α
2
(α+α
2
)=−p
3
⇒q+q
2
+3q(−p)=−p
3
⇒p
3
+q
2
+q(1−3p)=0