Α β γ are zeroes of cubic polynomial x3 12x2 44x c if α β γ are in ap find the value of c
Answers
The given polynomial is
p (x) = x³ + 12x² + 44x + c
Since, α, β and γ are the roots of p (x),
α + β + γ = - 12 ...(i)
αβ + βγ + γα = 44 ...(ii)
αβγ = - c ...(iii)
Given that, α, β and γ are in AP,
β - α = γ - α
or, 2α = β + γ ...(iv)
Now, (i) × 2 ⇒
2α + 2 (β + γ) = - 24
⇒ (β + γ) + 2 (β + γ) = - 24
⇒ 3 (β + γ) = - 24
⇒ β + γ = - 8 ...(v)
Now, putting β + γ = - 8 in (i), we get
α - 8 = - 12
⇒ α = - 12 + 8
⇒ α = - 4
Since α (= - 4) is a zero of p (x),
p (α) = 0
⇒ p (- 4) = 0
⇒ (- 4)³ + 12 (- 4)² + 44 (- 4) + c = 0
⇒ - 64 + 192 - 176 + c = 0
⇒ c = 48
Therefore, the value of c is 48.
#
Answer:
Step-by-step explanation:
Brainly.in
What is your question?
Secondary School Math 13+7 pts
Α β γ are zeroes of cubic polynomial x3 12x2 44x c if α β γ are in ap find the value of c
Report by PratyushRaman7252 26.05.2018
Answers
Lohi7092160609Ambitious
Know the answer? Add it here!
MarkAsBrainliest
MarkAsBrainliestEnglish Shakespeare
\textbf{Answer -}
The given polynomial is
p (x) = x³ + 12x² + 44x + c
Since, α, β and γ are the roots of p (x),
α + β + γ = - 12 ...(i)
αβ + βγ + γα = 44 ...(ii)
αβγ = - c ...(iii)
Given that, α, β and γ are in AP,
β - α = γ - α
or, 2α = β + γ ...(iv)
Now, (i) × 2 ⇒
2α + 2 (β + γ) = - 24
⇒ (β + γ) + 2 (β + γ) = - 24
⇒ 3 (β + γ) = - 24
⇒ β + γ = - 8 ...(v)
Now, putting β + γ = - 8 in (i), we get
α - 8 = - 12
⇒ α = - 12 + 8
⇒ α = - 4
Since α (= - 4) is a zero of p (x),
p (α) = 0
⇒ p (- 4) = 0
⇒ (- 4)³ + 12 (- 4)² + 44 (- 4) + c = 0
⇒ - 64 + 192 - 176 + c = 0
⇒ c = 48
Therefore, the value of c is 48