No products in the cart.

If one of zeros of cubic …

CBSE, JEE, NEET, CUET

CBSE, JEE, NEET, CUET

Question Bank, Mock Tests, Exam Papers

NCERT Solutions, Sample Papers, Notes, Videos

If one of zeros of cubic polynomial 'x^3+ax^2+bx+c' is (-1) then find the product of other two zeros
  • 1 answers

Sia ? 6 years, 7 months ago

Let p(x) = x3 + ax2 + bx + c
As -1 is one of the zeroes of p(x), p(-1) = 0
⇒ (-1)3 + a(-1)2 + b(-1) + c = 0
⇒ - 1 + a – b + c = 0
⇒ c = b –a + 1 …. (i)
Let  {tex}\alpha{/tex}, β be two other zeroes of p(x),
then product of zeroes =-1× {tex}\alpha{/tex} × β ={tex}\;\;-\frac{\;\;Cons\tan t\;term\;}{coefficient\;of\;x^3}{/tex}
⇒ (-1) (α β)  =  {tex}\;\;-\frac{\;\;c}1{/tex}
⇒ - {tex}\alpha{/tex} β = - c
⇒ {tex}\alpha{/tex} β = c
⇒ {tex}\alpha{/tex} β = b –a + 1 [using  (i)]
 Hence, the product of other two zeroes of the given cubic polynomial is b – a + 1.

https://examin8.com Test

Related Questions

sin60° cos 30°+ cos60° sin 30°
  • 2 answers
Find the nature of quadratic equation x^2 +x -5 =0
  • 0 answers
X-y=5
  • 1 answers
Prove that root 8 is an irration number
  • 2 answers
(A + B )²
  • 1 answers
Venu Gopal has twice
  • 0 answers

myCBSEguide App

myCBSEguide

Trusted by 1 Crore+ Students

Test Generator

Test Generator

Create papers online. It's FREE.

CUET Mock Tests

CUET Mock Tests

75,000+ questions to practice only on myCBSEguide app

Download myCBSEguide App